C-glycosyl tyrosines. Synthesis and incorporation into C-glycopeptides

Journal of Organic Chemistry

Volumn 64, Issue 15, 1999, Pages 5453-5462

  Pearce, Alan J ^a   Ramaya, Sharn ^a   Thorn, Simon N ^a   Bloomberg, Graham B ^a   Walter, Daryl S ^b   Gallagher, Timothy ^a  

^a UNIVERSITY OF BRISTOL   (United Kingdom)

^b ROCHE PRODUCTS LTD   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

GLYCOPEPTIDE; TYROSINE DERIVATIVE;

ARTICLE; CATALYSIS; CHEMICAL REACTION; CHEMICAL STRUCTURE; CONFORMATION; HYDROXYLATION; REACTION ANALYSIS; STEREOCHEMISTRY; STEREOISOMERISM; SYNTHESIS;

EID: 0033597840     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo990253e     Document Type: Article

References (90)

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2. Hughes R. G. Glycoproteins; Chapman and Hall: London, 1983. Jentoft, N. Trends Biochem. Sci. 1990, 15, 291. Lis, S.; Sharon, N. Eur. J. Biochem. 1993, 218, 1. Dwek, R. A. Chem. Rev. 1996, 96, 683. Meldal, M. In Neoglycoconjugates: Preparation and Application; Lee, Y. C., Lee, R. T., Eds.; Academic Press: San Diego, CA, 1994; p 145. Boons, G.-J.; Polt, R. L. In Carbohydrate Chemistry; Boons, G. J., Ed.; Blackie: London, 1998; p 223.
3. Hughes R. G. Glycoproteins; Chapman and Hall: London, 1983. Jentoft, N. Trends Biochem. Sci. 1990, 15, 291. Lis, S.; Sharon, N. Eur. J. Biochem. 1993, 218, 1. Dwek, R. A. Chem. Rev. 1996, 96, 683. Meldal, M. In Neoglycoconjugates: Preparation and Application; Lee, Y. C., Lee, R. T., Eds.; Academic Press: San Diego, CA, 1994; p 145. Boons, G.-J.; Polt, R. L. In Carbohydrate Chemistry; Boons, G. J., Ed.; Blackie: London, 1998; p 223.
4. Hughes R. G. Glycoproteins; Chapman and Hall: London, 1983. Jentoft, N. Trends Biochem. Sci. 1990, 15, 291. Lis, S.; Sharon, N. Eur. J. Biochem. 1993, 218, 1. Dwek, R. A. Chem. Rev. 1996, 96, 683. Meldal, M. In Neoglycoconjugates: Preparation and Application; Lee, Y. C., Lee, R. T., Eds.; Academic Press: San Diego, CA, 1994; p 145. Boons, G.-J.; Polt, R. L. In Carbohydrate Chemistry; Boons, G. J., Ed.; Blackie: London, 1998; p 223.
5. Hughes R. G. Glycoproteins; Chapman and Hall: London, 1983. Jentoft, N. Trends Biochem. Sci. 1990, 15, 291. Lis, S.; Sharon, N. Eur. J. Biochem. 1993, 218, 1. Dwek, R. A. Chem. Rev. 1996, 96, 683. Meldal, M. In Neoglycoconjugates: Preparation and Application; Lee, Y. C., Lee, R. T., Eds.; Academic Press: San Diego, CA, 1994; p 145. Boons, G.-J.; Polt, R. L. In Carbohydrate Chemistry; Boons, G. J., Ed.; Blackie: London, 1998; p 223.
6. Hughes R. G. Glycoproteins; Chapman and Hall: London, 1983. Jentoft, N. Trends Biochem. Sci. 1990, 15, 291. Lis, S.; Sharon, N. Eur. J. Biochem. 1993, 218, 1. Dwek, R. A. Chem. Rev. 1996, 96, 683. Meldal, M. In Neoglycoconjugates: Preparation and Application; Lee, Y. C., Lee, R. T., Eds.; Academic Press: San Diego, CA, 1994; p 145. Boons, G.-J.; Polt, R. L. In Carbohydrate Chemistry; Boons, G. J., Ed.; Blackie: London, 1998; p 223.
7. Levy D. E.; Tang, C. The Chemistry of C-Glycosides; Elsevier Science: Oxford, 1995. Postema, M. H. D. Tetrahedron 1992, 48, 8545. Postema, M. H. D. C-Glycoside Synthesis; CRC Press: London, 1995.
8. Levy D. E.; Tang, C. The Chemistry of C-Glycosides; Elsevier Science: Oxford, 1995. Postema, M. H. D. Tetrahedron 1992, 48, 8545. Postema, M. H. D. C-Glycoside Synthesis; CRC Press: London, 1995.
9. Levy D. E.; Tang, C. The Chemistry of C-Glycosides; Elsevier Science: Oxford, 1995. Postema, M. H. D. Tetrahedron 1992, 48, 8545. Postema, M. H. D. C-Glycoside Synthesis; CRC Press: London, 1995.
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11. Ravishankar, R.; Surolia, A.; Vijayan, M.; Lim, S.; Kishi, Y. J. Am. Chem. Soc. 1998, 112, 11297 and references therein. Rubinstein, G.; Sinaÿ, P.; Berthault, P. J. Phy. Chem. A 1997, 101, 2536. Espinosa, J.-F.; Montera, E.; Vian, A.; García, J. L.; Dietrich, H.; Schmidt, R. R.; Martín-Lomas, M.; Imberty, A.; Cañada, F. J.; Jiménez-Barbero, J. J. Am. Chem. Soc. 1998, 120, 1309 and references therein.
12. Ravishankar, R.; Surolia, A.; Vijayan, M.; Lim, S.; Kishi, Y. J. Am. Chem. Soc. 1998, 112, 11297 and references therein. Rubinstein, G.; Sinaÿ, P.; Berthault, P. J. Phy. Chem. A 1997, 101, 2536. Espinosa, J.-F.; Montera, E.; Vian, A.; García, J. L.; Dietrich, H.; Schmidt, R. R.; Martín-Lomas, M.; Imberty, A.; Cañada, F. J.; Jiménez-Barbero, J. J. Am. Chem. Soc. 1998, 120, 1309 and references therein.
13. Sparks, M. A.; Williams, K. W.; Whitesides, G. M. J. Med. Chem. 1993, 36, 778. Nagy, J. O.; Wang, P.; Gilbert, J. H.; Schaefer, M. E.; Hill, T. G.; Callstrom, M. R.; Bednarski, M. D. J. Med. Chem. 1992, 35, 4501. Michael, K.; Wittmann, V.; König, W.; Sandow J.; Kessler, H. Int. J. Pept. Protein Res. 1996, 48, 59. Bertozzi, C. R.; Cook, D. G.; Kobertz, W. R.; Gonzalez-Scarano, F.; Bednarski, M. D. J. Am. Chem. Soc. 1992, 114, 10639.
14. Sparks, M. A.; Williams, K. W.; Whitesides, G. M. J. Med. Chem. 1993, 36, 778. Nagy, J. O.; Wang, P.; Gilbert, J. H.; Schaefer, M. E.; Hill, T. G.; Callstrom, M. R.; Bednarski, M. D. J. Med. Chem. 1992, 35, 4501. Michael, K.; Wittmann, V.; König, W.; Sandow J.; Kessler, H. Int. J. Pept. Protein Res. 1996, 48, 59. Bertozzi, C. R.; Cook, D. G.; Kobertz, W. R.; Gonzalez-Scarano, F.; Bednarski, M. D. J. Am. Chem. Soc. 1992, 114, 10639.
15. Sparks, M. A.; Williams, K. W.; Whitesides, G. M. J. Med. Chem. 1993, 36, 778. Nagy, J. O.; Wang, P.; Gilbert, J. H.; Schaefer, M. E.; Hill, T. G.; Callstrom, M. R.; Bednarski, M. D. J. Med. Chem. 1992, 35, 4501. Michael, K.; Wittmann, V.; König, W.; Sandow J.; Kessler, H. Int. J. Pept. Protein Res. 1996, 48, 59. Bertozzi, C. R.; Cook, D. G.; Kobertz, W. R.; Gonzalez-Scarano, F.; Bednarski, M. D. J. Am. Chem. Soc. 1992, 114, 10639.
16. Sparks, M. A.; Williams, K. W.; Whitesides, G. M. J. Med. Chem. 1993, 36, 778. Nagy, J. O.; Wang, P.; Gilbert, J. H.; Schaefer, M. E.; Hill, T. G.; Callstrom, M. R.; Bednarski, M. D. J. Med. Chem. 1992, 35, 4501. Michael, K.; Wittmann, V.; König, W.; Sandow J.; Kessler, H. Int. J. Pept. Protein Res. 1996, 48, 59. Bertozzi, C. R.; Cook, D. G.; Kobertz, W. R.; Gonzalez-Scarano, F.; Bednarski, M. D. J. Am. Chem. Soc. 1992, 114, 10639.
17. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
18. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
19. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
20. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
21. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
22. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
23. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
24. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
25. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
26. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
27. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
28. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
29. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
30. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
31. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
32. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
33. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
34. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
35. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
36. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
37. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
38. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
39. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
40. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
41. A variety of C-glycosyl amino acids have been described: "anomeric" α-amino acids (a) Estevez, J. C.; Long, D. D.; Wormald, M. R.; Dwek, R. A.; Fleet, G. W. J. Tetrahedron Lett. 1995, 36, 8287. Substituted glycine variants (b) Simchen, G.; Pürkner, E. Synthesis 1990, 525. (c) Colombo, L.; Casiraghi, G.; Pittalis, A.; Rassu, G. J. Org. Chem. 1991, 56, 3897. (d) Garner, P.; Park, J. M. J. Org. Chem. 1990, 55, 3772. (e) Barrett, A. G. M.; Lebold, S. A. J. Org. Chem. 1990, 55, 3853. Substituted alanine variants. (f) Kessler, H.; Wittmann, V.; Köck, M.; Kottenhahn, M. Angew. Chem., Int. Ed. Engl. 1992, 31, 902. (g) Axon, J. R.; Beckwith, A. L. J. J. Chem. Soc., Chem. Commun. 1995, 549. (h) Gurjar, M. K.; Mainkar, A. S.; Syamala, M. Tetrahedron: Asymmetry 1993, 4, 2343. (i) Wang, L.; Fügedi, P.; Home, A. Abstr. Papers of Am. Chem. Soc. 1996, 212, 25-CARB. C-Linked variants of serine-based glycopeptides (j) Petrus, L.; BeMiller, J. N. Carbohydr. Res. 1992, 230, 197. (k) Bertozzi, C. R.; Hoeprich, P. D.; Bednarski, M. D. J. Org. Chem. 1992, 57, 6092 (see also ref 4). (l) Dorgan, B. J.; Jackson, R. F. W. Synlett 1996, 859. (m) Lay, L.; Meldal, M.; Nicotra, F.; Panza, L.; Russo, G. J. Chem. Soc., Chem. Commun. 1997, 1469. (n) Herpin,T. F.; Motherwell, W. B.; Weibel, J.-M. J. Chem. Soc., Chem. Commun. 1997, 923. (o) Debenham, S. D.; Debenham, J. S.; Burk, M. J.; Toone, E. J. J. Am. Chem. Soc. 1997, 119, 9897. (p) Fuchss. T.; Schmidt, R. R. Synthesis 1998, 753. (q) Urban, D.; Skyrdstrup, T.; Beau, J.-M. Chem. Commun. 1998, 955. (r) Arya, P.; Ben, R. N.; Qin, H. Tetrahedron Lett. 1998, 39, 6131. (s) Dondoni, A.; Marra, A.; Massi, A. Chem. Commun. 1998, 1741. (t) Dondoni, A.; Marra, A.; Massi, A. Tetrahedron 1998, 54, 2827. (u) Dondoni, A.; Massi, A.; Marra, A. Tetrahedron Lett. 1998, 39, 6601. (v) Dondoni, A.; Marra, A.; Massi, A. J. Org. Chem. 1999, 64, 933. More complex glycosyl amino acid derivatives (w) Hoffmann, M.; Burkhart, F.; Hessler, G.; Kessler, H. Helv. Chim. Acta 1996, 79, 1519. (x) Wang, L.-X.; Fan, J.-Q.; Lee, Y. C. Tetrahedron Lett. 1996, 37, 1975. (y) Burkhart, F.; Hoffmann, M.; Kessler, H. Angew. Chem., Int. Ed. Engl. 1997, 36, 1191.
42. C-Glycosylated dipeptides and related structures are known: (a) Sutherlin, D. P.; Stark, T. M.; Hughes, R.; Armstrong, R. W. J. Org. Chem. 1996, 61, 8350. (b) Arya, P.; Dion, S.; Shimizu, G. K. H. Bioorg. Med. Chem. Lett. 1997, 7, 1537. (c) Wang, L.-X.; Tang, M.; Suzuki, T.; Kitajima, K.; Inoue, Y.;
43. C-Glycosylated dipeptides and related structures are known: (a) Sutherlin, D. P.; Stark, T. M.; Hughes, R.; Armstrong, R. W. J. Org. Chem. 1996, 61, 8350. (b) Arya, P.; Dion, S.; Shimizu, G. K. H. Bioorg. Med. Chem. Lett. 1997, 7, 1537. (c) Wang, L.-X.; Tang, M.; Suzuki, T.; Kitajima, K.; Inoue, Y.; Inoue, S.; Fan, J.-Q.; Lee, Y. C. J. Am. Chem. Soc. 1997, 119, 11137. (d) Tedebark, U.; Meldal, M.; Panza, L.; Bock, K. Tetrahedron Lett. 1998, 39, 1815. (e) Lowary, T.; Meldal, M.; Helmbolt, A.; Vasella, A.; Bock, K. J. Org. Chem. 1998, 63, 9657.
44. C-Glycosylated dipeptides and related structures are known: (a) Sutherlin, D. P.; Stark, T. M.; Hughes, R.; Armstrong, R. W. J. Org. Chem. 1996, 61, 8350. (b) Arya, P.; Dion, S.; Shimizu, G. K. H. Bioorg. Med. Chem. Lett. 1997, 7, 1537. (c) Wang, L.-X.; Tang, M.; Suzuki, T.; Kitajima, K.; Inoue, Y.; Inoue, S.; Fan, J.-Q.; Lee, Y. C. J. Am. Chem. Soc. 1997, 119, 11137. (d) Tedebark, U.; Meldal, M.; Panza, L.; Bock, K. Tetrahedron Lett. 1998, 39, 1815. (e) Lowary, T.; Meldal, M.; Helmbolt, A.; Vasella, A.; Bock, K. J. Org. Chem. 1998, 63, 9657.
45. C-Glycosylated dipeptides and related structures are known: (a) Sutherlin, D. P.; Stark, T. M.; Hughes, R.; Armstrong, R. W. J. Org. Chem. 1996, 61, 8350. (b) Arya, P.; Dion, S.; Shimizu, G. K. H. Bioorg. Med. Chem. Lett. 1997, 7, 1537. (c) Wang, L.-X.; Tang, M.; Suzuki, T.; Kitajima, K.; Inoue, Y.; Inoue, S.; Fan, J.-Q.; Lee, Y. C. J. Am. Chem. Soc. 1997, 119, 11137. (d) Tedebark, U.; Meldal, M.; Panza, L.; Bock, K. Tetrahedron Lett. 1998, 39, 1815. (e) Lowary, T.; Meldal, M.; Helmbolt, A.; Vasella, A.; Bock, K. J. Org. Chem. 1998, 63, 9657.
46. C-Glycosylated dipeptides and related structures are known: (a) Sutherlin, D. P.; Stark, T. M.; Hughes, R.; Armstrong, R. W. J. Org. Chem. 1996, 61, 8350. (b) Arya, P.; Dion, S.; Shimizu, G. K. H. Bioorg. Med. Chem. Lett. 1997, 7, 1537. (c) Wang, L.-X.; Tang, M.; Suzuki, T.; Kitajima, K.; Inoue, Y.; Inoue, S.; Fan, J.-Q.; Lee, Y. C. J. Am. Chem. Soc. 1997, 119, 11137. (d) Tedebark, U.; Meldal, M.; Panza, L.; Bock, K. Tetrahedron Lett. 1998, 39, 1815. (e) Lowary, T.; Meldal, M.; Helmbolt, A.; Vasella, A.; Bock, K. J. Org. Chem. 1998, 63, 9657.
47. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
48. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
49. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
50. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
51. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
52. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
53. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
54. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
55. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
56. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
57. For occurrence and synthesis of O-glycosyl tyrosines and variants, see: (a) Williams, D. H.; Rajananda, V.; Williamson, M. P.; Bojesen, G. Top. Antibiot. Chem. 1980, 5, 119. (b) Kramer, K. J.; Hopkins, T. L.; Ahmed, R. F.; Mueller, D.; Lookhart, G. Arch. Biochem. Biophys. 1980, 205, 146. (c) Isobe, M.; Kondo, N.; Imai, K.; Yamashita, O.; Goto, T. Agric. Biol. Chem. 1981, 45, 687. (d) Lu, P.-W.; Kramer, K. J.; Seib, P. A.; Mueller, D. D.; Ahmed, R.; Hopkins, T. L. Insect Biochem. 1982, 12, 377. (e) Messner, P.; Christian, R.; Kolbe, J.; Schulz G.; Sleytr, U. B. J. Bacteriol. 1992, 174, 2236. (f) Lomako, J.; Lomako, W. M.; Whelan, W. J. Carbohydr. Res. 1992, 227, 331. (g) Morita, H.; Yamamiya, T.; Takeya, K.; Itokawa, H. Chem. Pharm. Bull. 1992, 40, 1352. (h) Rodriguez, I. R.; Whelan, W. J. Biochem. Biophys. Res. Commun. 1985, 132, 829. (i) Ahmad, S. A.; Hopkins, T. L.; Kramer, K. J. Insect Biochem. Mol. Biol. 1996, 26, 49. (j) Jansson, A. M.; Jensen, K. J.; Meldal, M.; Lomako, J.; Lomako, W. M.; Olsen C. E.; Bock, K. J. Chem. Soc., Perkin Trans. 1 1996, 1001. (k) Skelton, N. J.; Harding, M. M.; Mortishire-Smith, R. J.; Rahman, S. K.; Williams, D. H.; Rance M. J.; Ruddock, J. C. J. Am. Chem. Soc. 1991, 113, 7522.
58. Thorn, S. N.; Gallagher, T. Synlett 1996, 185. For a related application of this zinc methodology see ref 51.
59. 5,6 is also diagnostic of the "anomeric" configuration in C-glycosides of this type: Achmatowicz, O.; Bukowski, P. Rocz. Chem. 1973, 47, 99.
60. 5,6 is also diagnostic of the "anomeric" configuration in C-glycosides of this type: Achmatowicz, O.; Bukowski, P. Rocz. Chem. 1973, 47, 99.
61. 5,6 is also diagnostic of the "anomeric" configuration in C-glycosides of this type: Achmatowicz, O.; Bukowski, P. Rocz. Chem. 1973, 47, 99.
62. 5,6 is also diagnostic of the "anomeric" configuration in C-glycosides of this type: Achmatowicz, O.; Bukowski, P. Rocz. Chem. 1973, 47, 99.
63. 5,6 is also diagnostic of the "anomeric" configuration in C-glycosides of this type: Achmatowicz, O.; Bukowski, P. Rocz. Chem. 1973, 47, 99.
64. 5,6 is also diagnostic of the "anomeric" configuration in C-glycosides of this type: Achmatowicz, O.; Bukowski, P. Rocz. Chem. 1973, 47, 99.
65. Jackson, R. F. W.; Wishart, N.; Wood, A.; James, K.; Wythes, M. J. J. Org. Chem. 1992, 57, 3397. Jackson, R. F. W.; Turner, D.; Block, M. H. Synlett 1996, 862. Dunn, M. J.; Jackson, R. F. W.; Pietruszka, J.; Wishart, N.; Ellis, D.; Wythes, M. J. Synlett 1993, 499. Fraser, J. L.; Jackson R. F. W.; Porter, B. Synlett 1994, 379.
66. Jackson, R. F. W.; Wishart, N.; Wood, A.; James, K.; Wythes, M. J. J. Org. Chem. 1992, 57, 3397. Jackson, R. F. W.; Turner, D.; Block, M. H. Synlett 1996, 862. Dunn, M. J.; Jackson, R. F. W.; Pietruszka, J.; Wishart, N.; Ellis, D.; Wythes, M. J. Synlett 1993, 499. Fraser, J. L.; Jackson R. F. W.; Porter, B. Synlett 1994, 379.
67. Jackson, R. F. W.; Wishart, N.; Wood, A.; James, K.; Wythes, M. J. J. Org. Chem. 1992, 57, 3397. Jackson, R. F. W.; Turner, D.; Block, M. H. Synlett 1996, 862. Dunn, M. J.; Jackson, R. F. W.; Pietruszka, J.; Wishart, N.; Ellis, D.; Wythes, M. J. Synlett 1993, 499. Fraser, J. L.; Jackson R. F. W.; Porter, B. Synlett 1994, 379.
68. Jackson, R. F. W.; Wishart, N.; Wood, A.; James, K.; Wythes, M. J. J. Org. Chem. 1992, 57, 3397. Jackson, R. F. W.; Turner, D.; Block, M. H. Synlett 1996, 862. Dunn, M. J.; Jackson, R. F. W.; Pietruszka, J.; Wishart, N.; Ellis, D.; Wythes, M. J. Synlett 1993, 499. Fraser, J. L.; Jackson R. F. W.; Porter, B. Synlett 1994, 379.
69. For other applications of Pd-mediated cross coupling reactions of organozinc reagents in the synthesis of amino acids, see: Evans, D. A.; Bach, T. Angew. Chem., Int. Ed. Engl. 1993, 32, 1326. Walker, M. A.; Kaplita, K. P.; Chen, T.; King, H. D. Synlett 1997, 169. Malan, C.; Morin, C. Synlett 1996, 167.
70. For other applications of Pd-mediated cross coupling reactions of organozinc reagents in the synthesis of amino acids, see: Evans, D. A.; Bach, T. Angew. Chem., Int. Ed. Engl. 1993, 32, 1326. Walker, M. A.; Kaplita, K. P.; Chen, T.; King, H. D. Synlett 1997, 169. Malan, C.; Morin, C. Synlett 1996, 167.
71. For other applications of Pd-mediated cross coupling reactions of organozinc reagents in the synthesis of amino acids, see: Evans, D. A.; Bach, T. Angew. Chem., Int. Ed. Engl. 1993, 32, 1326. Walker, M. A.; Kaplita, K. P.; Chen, T.; King, H. D. Synlett 1997, 169. Malan, C.; Morin, C. Synlett 1996, 167.
72. Fraser-Reid, B.; Molino, B. F.; Magdzinski, L.; Mootoo, D. R. J. Org. Chem. 1987, 52, 4505. In the case of 6a we have carried out the dihydroxylation step (and O-acetylation) prior to the Pd-mediated coupling of 4 without deleterious effect. However, when applied to the L-rhamnal-derived C-glycoside 3c, while dihydroxylation/acetylation of this intermediate proceeded smoothly, the subsequent attempt at the Pd(0) coupling step (involving 4) surprisingly failed.
73. Attempts to rigorously purify 7 by chromatography led to extensive decompositon to give 2-(acetoxymethyl)furan, and 7 was prepared and used directly in crude form. The sensitivity of 7 under acidic C-glycosylation conditions has been noted: Byerley, A. L. J.; Kenwright, A. M.; Steel, P. G. Tetrahedron Lett. 1996, 37, 9092.
74. 2) resulted in an enhancement (2%) of 5-H, and irradiation of 6-H resulted in an enhancement (2%) of 2-H. No enhancement of 5-H was observed on irradiation of 2-H.
75. Dihydroxylation of 10 results in a mixture of both syn-diol isomers but only a marginal degree of diastereoselectivity was observed, and this has not been pursued.
76. Kunz, H. Angew. Chem., Int. Ed. Engl. 1987, 26, 294. Kihlberg J.; Elofsson, M. Curr. Med. Chem. 1997, 4, 85. Arsequell, G.; Valencia, G. Tetrahedron: Asymmetry 1997, 8, 2839. For the synthesis of peptides incorporating glycosylated tyrosine units, see: Varga, L.; Horvat, S.; Lemieux, C.; Schiller, P. W. Int. J. Pept. Protein Res. 1987, 30, 371. Horvat, S.; Varga L.; Horvat, J. Synthesis 1986, 209. Horvat, S.; Varga, L.; Horvat, J.; Pfützner, A.; Suhartono, H.; Rübsamen- Waigmann, H. Helv. Chim. Acta 1991, 74, 951.
77. Kunz, H. Angew. Chem., Int. Ed. Engl. 1987, 26, 294. Kihlberg J.; Elofsson, M. Curr. Med. Chem. 1997, 4, 85. Arsequell, G.; Valencia, G. Tetrahedron: Asymmetry 1997, 8, 2839. For the synthesis of peptides incorporating glycosylated tyrosine units, see: Varga, L.; Horvat, S.; Lemieux, C.; Schiller, P. W. Int. J. Pept. Protein Res. 1987, 30, 371. Horvat, S.; Varga L.; Horvat, J. Synthesis 1986, 209. Horvat, S.; Varga, L.; Horvat, J.; Pfützner, A.; Suhartono, H.; Rübsamen- Waigmann, H. Helv. Chim. Acta 1991, 74, 951.
78. Kunz, H. Angew. Chem., Int. Ed. Engl. 1987, 26, 294. Kihlberg J.; Elofsson, M. Curr. Med. Chem. 1997, 4, 85. Arsequell, G.; Valencia, G. Tetrahedron: Asymmetry 1997, 8, 2839. For the synthesis of peptides incorporating glycosylated tyrosine units, see: Varga, L.; Horvat, S.; Lemieux, C.; Schiller, P. W. Int. J. Pept. Protein Res. 1987, 30, 371. Horvat, S.; Varga L.; Horvat, J. Synthesis 1986, 209. Horvat, S.; Varga, L.; Horvat, J.; Pfützner, A.; Suhartono, H.; Rübsamen- Waigmann, H. Helv. Chim. Acta 1991, 74, 951.
79. Kunz, H. Angew. Chem., Int. Ed. Engl. 1987, 26, 294. Kihlberg J.; Elofsson, M. Curr. Med. Chem. 1997, 4, 85. Arsequell, G.; Valencia, G. Tetrahedron: Asymmetry 1997, 8, 2839. For the synthesis of peptides incorporating glycosylated tyrosine units, see: Varga, L.; Horvat, S.; Lemieux, C.; Schiller, P. W. Int. J. Pept. Protein Res. 1987, 30, 371. Horvat, S.; Varga L.; Horvat, J. Synthesis 1986, 209. Horvat, S.; Varga, L.; Horvat, J.; Pfützner, A.; Suhartono, H.; Rübsamen- Waigmann, H. Helv. Chim. Acta 1991, 74, 951.
80. Kunz, H. Angew. Chem., Int. Ed. Engl. 1987, 26, 294. Kihlberg J.; Elofsson, M. Curr. Med. Chem. 1997, 4, 85. Arsequell, G.; Valencia, G. Tetrahedron: Asymmetry 1997, 8, 2839. For the synthesis of peptides incorporating glycosylated tyrosine units, see: Varga, L.; Horvat, S.; Lemieux, C.; Schiller, P. W. Int. J. Pept. Protein Res. 1987, 30, 371. Horvat, S.; Varga L.; Horvat, J. Synthesis 1986, 209. Horvat, S.; Varga, L.; Horvat, J.; Pfützner, A.; Suhartono, H.; Rübsamen- Waigmann, H. Helv. Chim. Acta 1991, 74, 951.
81. Kunz, H. Angew. Chem., Int. Ed. Engl. 1987, 26, 294. Kihlberg J.; Elofsson, M. Curr. Med. Chem. 1997, 4, 85. Arsequell, G.; Valencia, G. Tetrahedron: Asymmetry 1997, 8, 2839. For the synthesis of peptides incorporating glycosylated tyrosine units, see: Varga, L.; Horvat, S.; Lemieux, C.; Schiller, P. W. Int. J. Pept. Protein Res. 1987, 30, 371. Horvat, S.; Varga L.; Horvat, J. Synthesis 1986, 209. Horvat, S.; Varga, L.; Horvat, J.; Pfützner, A.; Suhartono, H.; Rübsamen-Waigmann, H. Helv. Chim. Acta 1991, 74, 951.
82. Kopple, K. D.; Go, A.; Logan, R. H.; Savrda, J. J. Am. Chem. Soc. 1972, 94, 973. Tanizawa, K.; Okumura, K.; Itoh, H.; Hatanaka, Y.; Kanaoka, Y. Chem. Pharm. Bull. 1986, 34, 4001.
83. Kopple, K. D.; Go, A.; Logan, R. H.; Savrda, J. J. Am. Chem. Soc. 1972, 94, 973. Tanizawa, K.; Okumura, K.; Itoh, H.; Hatanaka, Y.; Kanaoka, Y. Chem. Pharm. Bull. 1986, 34, 4001.
84. 2} and of 14 are available in the Supporting Information.
85. 2} and of 14 are available in the Supporting Information.
86. 2} and of 14 are available in the Supporting Information.
87. 2} and of 14 are available in the Supporting Information.
88. For the application of the HOBt/TBTU method for the "head-to-tail" cyclization of linear hexapeptides, see: Zimmer, S.; Hoffmann, E.; Jung, G.; Kessler, H. Liebigs. Ann. Chem. 1993, 497.
89. 21
90. Leipert, D.; Nopper, D.; Bauser, M.; Gauglitz, G.; Jung, G. Angew. Chem., Int. Ed. Engl. 1998, 37, 3308.