Practical Synthesis of α-Amino Acid N-Carboxy Anhydrides of Polyhydroxylated α-Amino Acids from β-Lactam Frameworks. Model Studies toward the Synthesis of Directly Linked Peptidyl Nucleoside Antibiotics

Journal of Organic Chemistry

Volumn 63, Issue 17, 1998, Pages 5838-5846

  Palomo, Claudio ^a   Oiarbide, Mikel ^a   Esnal, Aitor ^a   Landa, Aitor ^a   Miranda, José I ^a   Linden, Anthony ^b  

^a UNIVERSITY OF THE BASQUE COUNTRY UPV EHU   (Spain)

^b UNIVERSITY OF ZURICH   (Switzerland)

Author keywords

[No Author keywords available]

Indexed keywords

ACID ANHYDRIDE; ALDEHYDE; ALPHA AMINO ACID; ANTIBIOTIC AGENT; BETA LACTAM; ESTER; IMINE; NUCLEOSIDE ANALOG; OXAMIC ACID;

ARTICLE; CHIRALITY; DRUG SYNTHESIS; PROTON NUCLEAR MAGNETIC RESONANCE; STEREOCHEMISTRY;

EID: 0032555405     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo980354x     Document Type: Article

References (64)

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6. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
7. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
8. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
9. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
10. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
11. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
12. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
13. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
14. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
15. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
16. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
17. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
18. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
19. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
20. For some additional examples on the synthesis of hydroxylated α-amino acids, see: (a) Shioiri, T.; Hamada, Y. Heterocycles 1988, 27, 1035. (b) Ariza, J.; Font, J.; Ortuño, R. M. In Trends Org. Chem. 1992, 3, 53. (c) Varela, O. Pure Appl. Chem. 1997, 69, 621. (d) Dondoni, A.; Perrone, D. Aldrichim. Acta 1997, 30, 35. (e) Rassu, G.; Zanardi, F.; Corria, M.; Casiragi, G. J. Chem. Soc., Perkin Trans. 1 1994, 2431. (f) Kirihata, M.; Nakao, Y.; Mori, M.; Ichimoto, I. Heterocycles 1995, 41, 2271. (g) Cativiela, C.; Díaz-de-Villegas, M. D.; Gálvez, J. A.; García, J. I. Tetrahedron 1996, 52, 9563. (h) Ojea, V.; Ruiz, M.; Quintela, J. M. Synlett 1997, 83. (i) Merino, P.; Franco, S.; Merchan, F. L.; Tejero, T. Tetrahedron: Asymmetry 1997, 8, 3489. (J) Kimura, T.; Vassilev, V. P.; Shen, G.-J.; Wong, C.-H. J. Am. Chem. Soc. 1997, 119, 11734. For general reviews on α-amino acid synthesis, including hydroxylated α-amino acids, see: (k) Williams, R. M. Synthesis of Optically Active α-Amino Acids; Pergamon Press: Oxford, 1988. (l) Duthaler, R. O. Tetrahedron 1994, 50, 1539. For α-amino acids from sugars, see: (m) Cintas, P. Tetrahedron 1991, 47, 6079. For α-amino acids from α-cation equivalents, see: (n) Bailey, P. D.; Clayson, J.; Boa, A. N. Contemp. Org. Synth. 1995, 2, 173. For a recent review on coupling methods for the incorporation of noncoded amino acids into peptides, see: (o) Humphrey, J. M.; Chamberlain, A. R. Chem. Rev. 1997, 97, 2243.
21. Palomo, C.; Oiarbide, M.; Esnal, A. Chem. Commun. 1997, 691.
22. For a conceptually different β-lactam route to the nonnatural enantiomer of polyoxamic acid, see ref 4k. For a recent review on the use of β-lactams as buildig-blocks of β-amino acid derivatives, see: Palomo, C.; Aizpurua, J. M.; Ganboa, I. In Enantioselective Synthesis of β-Amino Acids; Juaristi, E., Ed.; Wiley VCH: New York, 1997; p 279.
23. (a) Palomo, C.; Aizpurua, J. M.; Ganboa, I.; Carreaux, F.; Cuevas, C.; Maneiro, E.; Ontoria, J. M. J. Org. Chem. 1994, 59, 3123.
24. (b) Palomo, C.; Aizpurua, J. M.; Cuevas, C.; Urchegui, R.; Linden, A. J. Org. Chem. 1996, 61, 4400.
25. To date, the synthesis of NCA's invariably requires the prior construction of the desired α-amino acid followed by dehydration. For a detailed discussion on this topic, see: (a) Kricheldorf, H. R. α-Ammo Acid N-Carboxy-Anhydride and Related Heterocycles; Springer-Verlag: Berlin, 1987. (b) Reference 8a.
26. To date, the synthesis of NCA's invariably requires the prior construction of the desired α-amino acid followed by dehydration. For a detailed discussion on this topic, see: (a) Kricheldorf, H. R. α-Ammo Acid N-Carboxy-Anhydride and Related Heterocycles; Springer-Verlag: Berlin, 1987. (b) Reference 8a.
27. We adopted the term of glycoglycines instead of C-glycosylglycines according to the recent observation made by Dondoni, who indicated that the usual name of C-glycosyl α-amino acids appears appropriate only for compounds wherein the amino acid moiety is linked to the sugar anomeric carbon. See: Dondoni, A.; Junquera, F.; Merchán, F. L.; Merino, P.; Ascherrmann, M.-C.; Tejero, T. J. Org. Chem. 1997, 62, 5484.
28. For a review on ketene-imine cycloadditions, see: Georg, G. I.; Ravikumar, V. T. In The Organic Chemistry of β-Lactams; Georg, G. I., Ed.; VCH: New York, 1992; p 295. For a review on the construction of chiral molecules using α-hydroxy acids or aldehydes, see: Coppola, G. M.; Schuster, H. F. α-Hydroxy Acids in Enantioselective Syntheses; VCH: Weinheim, 1997.
29. For a review on ketene-imine cycloadditions, see: Georg, G. I.; Ravikumar, V. T. In The Organic Chemistry of β-Lactams; Georg, G. I., Ed.; VCH: New York, 1992; p 295. For a review on the construction of chiral molecules using α-hydroxy acids or aldehydes, see: Coppola, G. M.; Schuster, H. F. α-Hydroxy Acids in Enantioselective Syntheses; VCH: Weinheim, 1997.
30. Hubschwerlen, C.; Schmid, G. Helv. Chim. Acta 1983, 66, 2206.
31. (a) Wagle, D. R.; Garai, G.; Chiang, J.; Monteleone, M. G.; Kurys, B. E.; Strohmeyer, T. W.; Hedge, V. R.; Mahnas, M. S.; Bose, A. K. J. Org. Chem. 1988, 53, 4227.
32. (b) Banik, B. K.; Manhas, M. S.; Kaluza, Z.; Barakat, J. K.; Bose, A. K. Tetrahedron Lett. 1992, 33, 3603.
33. For the use of this imine in the synthesis of 3-amino β-lactams, via the cycloaddition approach, see: Saito, S.; Ishikawa, T.; Morinake, T. Synlett 1993, 139.
34. Tabusa, F.; Yamada, T.; Suzuki, K.; Mukaiyama, T. Chem. Lett. 1984, 405. See also ref 4c.
35. NCA 11 and 16 rapidly became white solids and could be stored under nitrogen in a cool room for several days without appreciable decomposition. All other NCAs so far described in this article did not solidify easily and were used within a few hours of isolation.
36. The imine was prepared from the commercially available methyl 3,4-O-isopropylidene-L-threonate by standard teri-butyldimethylsilylation of the secondary hydroxy group and subsequent reduction of the methyl ester by treatment with DIBAL at -78 °C in toluene. The resulting aldehyde was treated with equimolar amounts of benzylamine in methylene chloride in the presence of magnesium sulfate at 0 °C for 1 h. After usual workup, the crude imine was used as such.
37. Jayaraman, M.; Deshmukh, A. R. A. S.; Bhawal, B. M. J. Org. Chem. 1994, 59, 932.
38. For some representative reviews, see: (a) Erickson, J. W. Perspect. Drug Discovery Des. 1993, 1, 109. (b) Abdel-meguid, S. S. Med. Res. Rev. 1993, 6, 731. (c) March, D. R.; Fairlie, D. P. In Designing New Antiviral Drugs for AIDS: HIV-1 Protease and Its Inhibitors; Wise, R., Ed.; R. G. Landes Publishers: Austin, TX, 1996; p 1. (d) Dorsch, D.; Raddatz, P.; Schmitges, C.-d.; von der Helm, K.; Rippmann, F. Kontackte 1993, 48.
39. For some representative reviews, see: (a) Erickson, J. W. Perspect. Drug Discovery Des. 1993, 1, 109. (b) Abdel-meguid, S. S. Med. Res. Rev. 1993, 6, 731. (c) March, D. R.; Fairlie, D. P. In Designing New Antiviral Drugs for AIDS: HIV-1 Protease and Its Inhibitors; Wise, R., Ed.; R. G. Landes Publishers: Austin, TX, 1996; p 1. (d) Dorsch, D.; Raddatz, P.; Schmitges, C.-d.; von der Helm, K.; Rippmann, F. Kontackte 1993, 48.
40. For some representative reviews, see: (a) Erickson, J. W. Perspect. Drug Discovery Des. 1993, 1, 109. (b) Abdel-meguid, S. S. Med. Res. Rev. 1993, 6, 731. (c) March, D. R.; Fairlie, D. P. In Designing New Antiviral Drugs for AIDS: HIV-1 Protease and Its Inhibitors; Wise, R., Ed.; R. G. Landes Publishers: Austin, TX, 1996; p 1. (d) Dorsch, D.; Raddatz, P.; Schmitges, C.-d.; von der Helm, K.; Rippmann, F. Kontackte 1993, 48.
41. For some representative reviews, see: (a) Erickson, J. W. Perspect. Drug Discovery Des. 1993, 1, 109. (b) Abdel-meguid, S. S. Med. Res. Rev. 1993, 6, 731. (c) March, D. R.; Fairlie, D. P. In Designing New Antiviral Drugs for AIDS: HIV-1 Protease and Its Inhibitors; Wise, R., Ed.; R. G. Landes Publishers: Austin, TX, 1996; p 1. (d) Dorsch, D.; Raddatz, P.; Schmitges, C.-d.; von der Helm, K.; Rippmann, F. Kontackte 1993, 48.
42. 2-symmetric cyclic urea as intermediate in the synthesis of HIV-protease inhibitors; see: Schreiner, E. P.; Pruckner, A. J. Org. Chem. 1997, 62, 5380.
43. For the syntheses of α-aminofuranuronic acids, see: (a) ref 4g, 10, and references therein. (b) Bouifraden, S.; Lavergne, J.-P.; Martínez, J.; Viallefont, P.; Riche, C. Tetrahedron: Asymmetry 1997, 8, 949. (c) Bouifraden, S.; Lavergne, J.-P.; Martinez, J.; Viallefont, P. Synth. Commun. 1997, 27, 3909. (d) Gethin, D. M.; Simpkins, N. S. Tetrahedron 1997, 53, 14417.
44. For the syntheses of α-aminofuranuronic acids, see: (a) ref 4g, 10, and references therein. (b) Bouifraden, S.; Lavergne, J.-P.; Martínez, J.; Viallefont, P.; Riche, C. Tetrahedron: Asymmetry 1997, 8, 949. (c) Bouifraden, S.; Lavergne, J.-P.; Martinez, J.; Viallefont, P. Synth. Commun. 1997, 27, 3909. (d) Gethin, D. M.; Simpkins, N. S. Tetrahedron 1997, 53, 14417.
45. For the syntheses of α-aminofuranuronic acids, see: (a) ref 4g, 10, and references therein. (b) Bouifraden, S.; Lavergne, J.-P.; Martínez, J.; Viallefont, P.; Riche, C. Tetrahedron: Asymmetry 1997, 8, 949. (c) Bouifraden, S.; Lavergne, J.-P.; Martinez, J.; Viallefont, P. Synth. Commun. 1997, 27, 3909. (d) Gethin, D. M.; Simpkins, N. S. Tetrahedron 1997, 53, 14417.
46. For the syntheses of α-aminofuranuronic acids, see: (a) ref 4g, 10, and references therein. (b) Bouifraden, S.; Lavergne, J.-P.; Martínez, J.; Viallefont, P.; Riche, C. Tetrahedron: Asymmetry 1997, 8, 949. (c) Bouifraden, S.; Lavergne, J.-P.; Martinez, J.; Viallefont, P. Synth. Commun. 1997, 27, 3909. (d) Gethin, D. M.; Simpkins, N. S. Tetrahedron 1997, 53, 14417.
47. Wayle, D. R.; Garai, C.; Monteleone, M. G.; Bose, A. K. Tetrahedron Lett. 1988, 29, 1649.
48. Attempts to epimerize the amino acid ester at the α-position through the benzaldimine intermediate were unsuccessful, and the starting material was recovered without change. For this epimerization process, see: (a) Clark, J. C.; Phillipps, G. H.; Steer, M. R. J. Chem. Soc., Perkin Trans. 1 1976, 475. (b) Honnoraty, A.-M.; Mion, L.; Collet, H.; Teissedre, R.; Commeyras, A. Bull. Soc. Chim. Fr. 1995, 132, 709.
49. Attempts to epimerize the amino acid ester at the α-position through the benzaldimine intermediate were unsuccessful, and the starting material was recovered without change. For this epimerization process, see: (a) Clark, J. C.; Phillipps, G. H.; Steer, M. R. J. Chem. Soc., Perkin Trans. 1 1976, 475. (b) Honnoraty, A.-M.; Mion, L.; Collet, H.; Teissedre, R.; Commeyras, A. Bull. Soc. Chim. Fr. 1995, 132, 709.
50. For a mechanistic discussion on this subject, see: (a) Palomo, C.; Cossío, F. P, Cuevas, C.; Lecea, B.; Mielgo, A.; Román, P.; Luque, A.; Martínez-Ripoll, M. J. Am. Chem. Soc. 1992, 114, 9360. (b) Cossío, F. P., Arrieta, A.; Lecea, B.; Ugalde, J. M. J. Am. Chem. Soc. 1994, 116, 2085. For further experimental evidence on the stereochemical outcome of cycloaddition reactions involving α-oxy aldehyde-derived imines, see: (c) Palomo, C.; Cossío, F. P.; Ontoria, J. M.; Odriozola, J. M. Tetrahedron Lett. 1991, 32, 3105. (d) Brown, A. D.; Colvin, E. W. Tetrahedron Lett. 1991, 32, 5187. (e) Kobayashi, Y.; Takemoto, Y.; Kamijo, T.; Harada, H.; Ito, Y.; Terashima, S. Tetrahedron 1992, 48, 1853. (f) Palomo, C.; Aizpurua, J. M.; Urchegui, R.; García, J. M. J. Org. Chem. 1993, 58, 1646. (g) Alcaide, B.; Miranda, M.; Pérez-Castells, J.; Polanco, C.; Sierra, M. A. J. Org. Chem. 1994, 59, 8003. (h) Kramer, B.; Franz, T.; Picasso, S.; Pruschek, P.; Jager, V. Synlett 1997, 295.
51. For a mechanistic discussion on this subject, see: (a) Palomo, C.; Cossío, F. P, Cuevas, C.; Lecea, B.; Mielgo, A.; Román, P.; Luque, A.; Martínez-Ripoll, M. J. Am. Chem. Soc. 1992, 114, 9360. (b) Cossío, F. P., Arrieta, A.; Lecea, B.; Ugalde, J. M. J. Am. Chem. Soc. 1994, 116, 2085. For further experimental evidence on the stereochemical outcome of cycloaddition reactions involving α-oxy aldehyde-derived imines, see: (c) Palomo, C.; Cossío, F. P.; Ontoria, J. M.; Odriozola, J. M. Tetrahedron Lett. 1991, 32, 3105. (d) Brown, A. D.; Colvin, E. W. Tetrahedron Lett. 1991, 32, 5187. (e) Kobayashi, Y.; Takemoto, Y.; Kamijo, T.; Harada, H.; Ito, Y.; Terashima, S. Tetrahedron 1992, 48, 1853. (f) Palomo, C.; Aizpurua, J. M.; Urchegui, R.; García, J. M. J. Org. Chem. 1993, 58, 1646. (g) Alcaide, B.; Miranda, M.; Pérez-Castells, J.; Polanco, C.; Sierra, M. A. J. Org. Chem. 1994, 59, 8003. (h) Kramer, B.; Franz, T.; Picasso, S.; Pruschek, P.; Jager, V. Synlett 1997, 295.
52. For a mechanistic discussion on this subject, see: (a) Palomo, C.; Cossío, F. P, Cuevas, C.; Lecea, B.; Mielgo, A.; Román, P.; Luque, A.; Martínez-Ripoll, M. J. Am. Chem. Soc. 1992, 114, 9360. (b) Cossío, F. P., Arrieta, A.; Lecea, B.; Ugalde, J. M. J. Am. Chem. Soc. 1994, 116, 2085. For further experimental evidence on the stereochemical outcome of cycloaddition reactions involving α-oxy aldehyde-derived imines, see: (c) Palomo, C.; Cossío, F. P.; Ontoria, J. M.; Odriozola, J. M. Tetrahedron Lett. 1991, 32, 3105. (d) Brown, A. D.; Colvin, E. W. Tetrahedron Lett. 1991, 32, 5187. (e) Kobayashi, Y.; Takemoto, Y.; Kamijo, T.; Harada, H.; Ito, Y.; Terashima, S. Tetrahedron 1992, 48, 1853. (f) Palomo, C.; Aizpurua, J. M.; Urchegui, R.; García, J. M. J. Org. Chem. 1993, 58, 1646. (g) Alcaide, B.; Miranda, M.; Pérez-Castells, J.; Polanco, C.; Sierra, M. A. J. Org. Chem. 1994, 59, 8003. (h) Kramer, B.; Franz, T.; Picasso, S.; Pruschek, P.; Jager, V. Synlett 1997, 295.
53. For a mechanistic discussion on this subject, see: (a) Palomo, C.; Cossío, F. P, Cuevas, C.; Lecea, B.; Mielgo, A.; Román, P.; Luque, A.; Martínez-Ripoll, M. J. Am. Chem. Soc. 1992, 114, 9360. (b) Cossío, F. P., Arrieta, A.; Lecea, B.; Ugalde, J. M. J. Am. Chem. Soc. 1994, 116, 2085. For further experimental evidence on the stereochemical outcome of cycloaddition reactions involving α-oxy aldehyde-derived imines, see: (c) Palomo, C.; Cossío, F. P.; Ontoria, J. M.; Odriozola, J. M. Tetrahedron Lett. 1991, 32, 3105. (d) Brown, A. D.; Colvin, E. W. Tetrahedron Lett. 1991, 32, 5187. (e) Kobayashi, Y.; Takemoto, Y.; Kamijo, T.; Harada, H.; Ito, Y.; Terashima, S. Tetrahedron 1992, 48, 1853. (f) Palomo, C.; Aizpurua, J. M.; Urchegui, R.; García, J. M. J. Org. Chem. 1993, 58, 1646. (g) Alcaide, B.; Miranda, M.; Pérez-Castells, J.; Polanco, C.; Sierra, M. A. J. Org. Chem. 1994, 59, 8003. (h) Kramer, B.; Franz, T.; Picasso, S.; Pruschek, P.; Jager, V. Synlett 1997, 295.
54. For a mechanistic discussion on this subject, see: (a) Palomo, C.; Cossío, F. P, Cuevas, C.; Lecea, B.; Mielgo, A.; Román, P.; Luque, A.; Martínez-Ripoll, M. J. Am. Chem. Soc. 1992, 114, 9360. (b) Cossío, F. P., Arrieta, A.; Lecea, B.; Ugalde, J. M. J. Am. Chem. Soc. 1994, 116, 2085. For further experimental evidence on the stereochemical outcome of cycloaddition reactions involving α-oxy aldehyde-derived imines, see: (c) Palomo, C.; Cossío, F. P.; Ontoria, J. M.; Odriozola, J. M. Tetrahedron Lett. 1991, 32, 3105. (d) Brown, A. D.; Colvin, E. W. Tetrahedron Lett. 1991, 32, 5187. (e) Kobayashi, Y.; Takemoto, Y.; Kamijo, T.; Harada, H.; Ito, Y.; Terashima, S. Tetrahedron 1992, 48, 1853. (f) Palomo, C.; Aizpurua, J. M.; Urchegui, R.; García, J. M. J. Org. Chem. 1993, 58, 1646. (g) Alcaide, B.; Miranda, M.; Pérez-Castells, J.; Polanco, C.; Sierra, M. A. J. Org. Chem. 1994, 59, 8003. (h) Kramer, B.; Franz, T.; Picasso, S.; Pruschek, P.; Jager, V. Synlett 1997, 295.
55. For a mechanistic discussion on this subject, see: (a) Palomo, C.; Cossío, F. P, Cuevas, C.; Lecea, B.; Mielgo, A.; Román, P.; Luque, A.; Martínez-Ripoll, M. J. Am. Chem. Soc. 1992, 114, 9360. (b) Cossío, F. P., Arrieta, A.; Lecea, B.; Ugalde, J. M. J. Am. Chem. Soc. 1994, 116, 2085. For further experimental evidence on the stereochemical outcome of cycloaddition reactions involving α-oxy aldehyde-derived imines, see: (c) Palomo, C.; Cossío, F. P.; Ontoria, J. M.; Odriozola, J. M. Tetrahedron Lett. 1991, 32, 3105. (d) Brown, A. D.; Colvin, E. W. Tetrahedron Lett. 1991, 32, 5187. (e) Kobayashi, Y.; Takemoto, Y.; Kamijo, T.; Harada, H.; Ito, Y.; Terashima, S. Tetrahedron 1992, 48, 1853. (f) Palomo, C.; Aizpurua, J. M.; Urchegui, R.; García, J. M. J. Org. Chem. 1993, 58, 1646. (g) Alcaide, B.; Miranda, M.; Pérez-Castells, J.; Polanco, C.; Sierra, M. A. J. Org. Chem. 1994, 59, 8003. (h) Kramer, B.; Franz, T.; Picasso, S.; Pruschek, P.; Jager, V. Synlett 1997, 295.
56. For a mechanistic discussion on this subject, see: (a) Palomo, C.; Cossío, F. P, Cuevas, C.; Lecea, B.; Mielgo, A.; Román, P.; Luque, A.; Martínez-Ripoll, M. J. Am. Chem. Soc. 1992, 114, 9360. (b) Cossío, F. P., Arrieta, A.; Lecea, B.; Ugalde, J. M. J. Am. Chem. Soc. 1994, 116, 2085. For further experimental evidence on the stereochemical outcome of cycloaddition reactions involving α-oxy aldehyde-derived imines, see: (c) Palomo, C.; Cossío, F. P.; Ontoria, J. M.; Odriozola, J. M. Tetrahedron Lett. 1991, 32, 3105. (d) Brown, A. D.; Colvin, E. W. Tetrahedron Lett. 1991, 32, 5187. (e) Kobayashi, Y.; Takemoto, Y.; Kamijo, T.; Harada, H.; Ito, Y.; Terashima, S. Tetrahedron 1992, 48, 1853. (f) Palomo, C.; Aizpurua, J. M.; Urchegui, R.; García, J. M. J. Org. Chem. 1993, 58, 1646. (g) Alcaide, B.; Miranda, M.; Pérez-Castells, J.; Polanco, C.; Sierra, M. A. J. Org. Chem. 1994, 59, 8003. (h) Kramer, B.; Franz, T.; Picasso, S.; Pruschek, P.; Jager, V. Synlett 1997, 295.
57. For a mechanistic discussion on this subject, see: (a) Palomo, C.; Cossío, F. P, Cuevas, C.; Lecea, B.; Mielgo, A.; Román, P.; Luque, A.; Martínez-Ripoll, M. J. Am. Chem. Soc. 1992, 114, 9360. (b) Cossío, F. P., Arrieta, A.; Lecea, B.; Ugalde, J. M. J. Am. Chem. Soc. 1994, 116, 2085. For further experimental evidence on the stereochemical outcome of cycloaddition reactions involving α-oxy aldehyde-derived imines, see: (c) Palomo, C.; Cossío, F. P.; Ontoria, J. M.; Odriozola, J. M. Tetrahedron Lett. 1991, 32, 3105. (d) Brown, A. D.; Colvin, E. W. Tetrahedron Lett. 1991, 32, 5187. (e) Kobayashi, Y.; Takemoto, Y.; Kamijo, T.; Harada, H.; Ito, Y.; Terashima, S. Tetrahedron 1992, 48, 1853. (f) Palomo, C.; Aizpurua, J. M.; Urchegui, R.; García, J. M. J. Org. Chem. 1993, 58, 1646. (g) Alcaide, B.; Miranda, M.; Pérez-Castells, J.; Polanco, C.; Sierra, M. A. J. Org. Chem. 1994, 59, 8003. (h) Kramer, B.; Franz, T.; Picasso, S.; Pruschek, P.; Jager, V. Synlett 1997, 295.
58. These results contrast with those previously reported by Bose and his colleagues who achieved a complete diastereoselectivity in the reactions of alkoxyketenes with the imine 44. For pertinent information, see: (a) Bose, A. K.; Mathur, C.; Wagle, D. R.; Nagui, R.; Manhas, M. S. Heterocycles 1994, 39, 491. (b) Kaluza, Z.; Manhas, M. S.; Barakat, K. J.; Bose, A. K. Biorg. Med. Chem. Lett. 1993, 3, 2357.
59. These results contrast with those previously reported by Bose and his colleagues who achieved a complete diastereoselectivity in the reactions of alkoxyketenes with the imine 44. For pertinent information, see: (a) Bose, A. K.; Mathur, C.; Wagle, D. R.; Nagui, R.; Manhas, M. S. Heterocycles 1994, 39, 491. (b) Kaluza, Z.; Manhas, M. S.; Barakat, K. J.; Bose, A. K. Biorg. Med. Chem. Lett. 1993, 3, 2357.
60. For the synthesis of α-aminopyranuronic acids, see: (a) ref 10 and references therein. (b) Czerniecki, S.; Horns, S.; Valery, J.-M. J. Org. Chem. 1995, 60, 650. (c) Czerniecki, S.; Franco, S.; Horns, S.; Valery, J.-M. Tetrahedron Lett. 1996, 37, 4003. (d) Czerniecki, S.; Franco, S.; Valery, J.-M. J. Org. Chem. 1997, 62, 4845.
61. For the synthesis of α-aminopyranuronic acids, see: (a) ref 10 and references therein. (b) Czerniecki, S.; Horns, S.; Valery, J.-M. J. Org. Chem. 1995, 60, 650. (c) Czerniecki, S.; Franco, S.; Horns, S.; Valery, J.-M. Tetrahedron Lett. 1996, 37, 4003. (d) Czerniecki, S.; Franco, S.; Valery, J.-M. J. Org. Chem. 1997, 62, 4845.
62. For the synthesis of α-aminopyranuronic acids, see: (a) ref 10 and references therein. (b) Czerniecki, S.; Horns, S.; Valery, J.-M. J. Org. Chem. 1995, 60, 650. (c) Czerniecki, S.; Franco, S.; Horns, S.; Valery, J.-M. Tetrahedron Lett. 1996, 37, 4003. (d) Czerniecki, S.; Franco, S.; Valery, J.-M. J. Org. Chem. 1997, 62, 4845.
63. For the synthesis of α-aminopyranuronic acids, see: (a) ref 10 and references therein. (b) Czerniecki, S.; Horns, S.; Valery, J.-M. J. Org. Chem. 1995, 60, 650. (c) Czerniecki, S.; Franco, S.; Horns, S.; Valery, J.-M. Tetrahedron Lett. 1996, 37, 4003. (d) Czerniecki, S.; Franco, S.; Valery, J.-M. J. Org. Chem. 1997, 62, 4845.
64. The X-ray crystal structure analyses have been performed by one of us (A.L.) at the Organisch-chemisches Institut der Universität Zürich. Atomic coordinates, bond lengths and angles, and thermal parameters for compounds 34, 39, and 48 have been deposited at the Cambridge Crystallographic Data Center. The coordinates can be obtained, on request, from the Director, Cambridge Crystallographic Data Center, 12 Union Road, Cambridge, CB2, 1EZ, UK. E-mail: deposit@ccdc.cam.ac.uk.