Chemistry of trichlorosilyl enolates. 1. New reagents for catalytic, asymmetric aldol additions

Journal of the American Chemical Society

Volumn 118, Issue 31, 1996, Pages 7404-7405

  Denmark, Scott E ^a   Winter, Stephen B D ^a   Su, Xiping ^a   Wong, Ken Tsung ^a  

^a UNIVERSITY OF ILLINOIS AT URBANA CHAMPAIGN   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

CARBOXYLIC ACID DERIVATIVE; KETONE;

ARTICLE; CATALYSIS; DRUG SYNTHESIS; REACTION ANALYSIS;

EID: 0029764219     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja9606539     Document Type: Article

References (46)

1. For reviews of enantioselective aldol additions see: (a) Evans, D. A.; Nelson, J. V.; Taber, T. R. In Topics in Stereochemistry; Eliel, E. L., Allinger, N. L., Wilen, S. H., Eds.; Wiley Interscience: New York, 1982; Vol. 13, p 1. (b) Heathcock, C. H. In Comprehensive Carbanion Chemistry; Buncel, E., Durst, T., Eds.; Elsevier: New York, 1984; Vol. 5B, p 177. (c) Heathcock, C. H. In Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: New York, 1984; Vol 3, Chapter 2. (d) Kim, B. M.; Williams, S. F.; Masamune, S. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 239-275. (e) Gennari, C. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 629-660. (f) Bach, T. Angew. Chem, Int. Ed. Engl. 1994, 33, 417. (g) Franklin, A. S.; Paterson, I. Contemp. Org. Synth. 1994, 1, 317-416. (h) Braun, M.; Sacha, H. J. Prakt. Chem. 1993, 335, 653-668. (i) Sawamura, M.; Ito, Y. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: New York, 1993; pp 367-388.
2. For reviews of enantioselective aldol additions see: (a) Evans, D. A.; Nelson, J. V.; Taber, T. R. In Topics in Stereochemistry; Eliel, E. L., Allinger, N. L., Wilen, S. H., Eds.; Wiley Interscience: New York, 1982; Vol. 13, p 1. (b) Heathcock, C. H. In Comprehensive Carbanion Chemistry; Buncel, E., Durst, T., Eds.; Elsevier: New York, 1984; Vol. 5B, p 177. (c) Heathcock, C. H. In Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: New York, 1984; Vol 3, Chapter 2. (d) Kim, B. M.; Williams, S. F.; Masamune, S. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 239-275. (e) Gennari, C. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 629-660. (f) Bach, T. Angew. Chem, Int. Ed. Engl. 1994, 33, 417. (g) Franklin, A. S.; Paterson, I. Contemp. Org. Synth. 1994, 1, 317-416. (h) Braun, M.; Sacha, H. J. Prakt. Chem. 1993, 335, 653-668. (i) Sawamura, M.; Ito, Y. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: New York, 1993; pp 367-388.
3. For reviews of enantioselective aldol additions see: (a) Evans, D. A.; Nelson, J. V.; Taber, T. R. In Topics in Stereochemistry; Eliel, E. L., Allinger, N. L., Wilen, S. H., Eds.; Wiley Interscience: New York, 1982; Vol. 13, p 1. (b) Heathcock, C. H. In Comprehensive Carbanion Chemistry; Buncel, E., Durst, T., Eds.; Elsevier: New York, 1984; Vol. 5B, p 177. (c) Heathcock, C. H. In Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: New York, 1984; Vol 3, Chapter 2. (d) Kim, B. M.; Williams, S. F.; Masamune, S. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 239-275. (e) Gennari, C. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 629-660. (f) Bach, T. Angew. Chem, Int. Ed. Engl. 1994, 33, 417. (g) Franklin, A. S.; Paterson, I. Contemp. Org. Synth. 1994, 1, 317-416. (h) Braun, M.; Sacha, H. J. Prakt. Chem. 1993, 335, 653-668. (i) Sawamura, M.; Ito, Y. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: New York, 1993; pp 367-388.
4. For reviews of enantioselective aldol additions see: (a) Evans, D. A.; Nelson, J. V.; Taber, T. R. In Topics in Stereochemistry; Eliel, E. L., Allinger, N. L., Wilen, S. H., Eds.; Wiley Interscience: New York, 1982; Vol. 13, p 1. (b) Heathcock, C. H. In Comprehensive Carbanion Chemistry; Buncel, E., Durst, T., Eds.; Elsevier: New York, 1984; Vol. 5B, p 177. (c) Heathcock, C. H. In Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: New York, 1984; Vol 3, Chapter 2. (d) Kim, B. M.; Williams, S. F.; Masamune, S. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 239-275. (e) Gennari, C. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 629-660. (f) Bach, T. Angew. Chem, Int. Ed. Engl. 1994, 33, 417. (g) Franklin, A. S.; Paterson, I. Contemp. Org. Synth. 1994, 1, 317-416. (h) Braun, M.; Sacha, H. J. Prakt. Chem. 1993, 335, 653-668. (i) Sawamura, M.; Ito, Y. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: New York, 1993; pp 367-388.
5. For reviews of enantioselective aldol additions see: (a) Evans, D. A.; Nelson, J. V.; Taber, T. R. In Topics in Stereochemistry; Eliel, E. L., Allinger, N. L., Wilen, S. H., Eds.; Wiley Interscience: New York, 1982; Vol. 13, p 1. (b) Heathcock, C. H. In Comprehensive Carbanion Chemistry; Buncel, E., Durst, T., Eds.; Elsevier: New York, 1984; Vol. 5B, p 177. (c) Heathcock, C. H. In Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: New York, 1984; Vol 3, Chapter 2. (d) Kim, B. M.; Williams, S. F.; Masamune, S. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 239-275. (e) Gennari, C. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 629-660. (f) Bach, T. Angew. Chem, Int. Ed. Engl. 1994, 33, 417. (g) Franklin, A. S.; Paterson, I. Contemp. Org. Synth. 1994, 1, 317-416. (h) Braun, M.; Sacha, H. J. Prakt. Chem. 1993, 335, 653-668. (i) Sawamura, M.; Ito, Y. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: New York, 1993; pp 367-388.
6. For reviews of enantioselective aldol additions see: (a) Evans, D. A.; Nelson, J. V.; Taber, T. R. In Topics in Stereochemistry; Eliel, E. L., Allinger, N. L., Wilen, S. H., Eds.; Wiley Interscience: New York, 1982; Vol. 13, p 1. (b) Heathcock, C. H. In Comprehensive Carbanion Chemistry; Buncel, E., Durst, T., Eds.; Elsevier: New York, 1984; Vol. 5B, p 177. (c) Heathcock, C. H. In Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: New York, 1984; Vol 3, Chapter 2. (d) Kim, B. M.; Williams, S. F.; Masamune, S. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 239-275. (e) Gennari, C. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 629-660. (f) Bach, T. Angew. Chem, Int. Ed. Engl. 1994, 33, 417. (g) Franklin, A. S.; Paterson, I. Contemp. Org. Synth. 1994, 1, 317-416. (h) Braun, M.; Sacha, H. J. Prakt. Chem. 1993, 335, 653-668. (i) Sawamura, M.; Ito, Y. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: New York, 1993; pp 367-388.
7. For reviews of enantioselective aldol additions see: (a) Evans, D. A.; Nelson, J. V.; Taber, T. R. In Topics in Stereochemistry; Eliel, E. L., Allinger, N. L., Wilen, S. H., Eds.; Wiley Interscience: New York, 1982; Vol. 13, p 1. (b) Heathcock, C. H. In Comprehensive Carbanion Chemistry; Buncel, E., Durst, T., Eds.; Elsevier: New York, 1984; Vol. 5B, p 177. (c) Heathcock, C. H. In Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: New York, 1984; Vol 3, Chapter 2. (d) Kim, B. M.; Williams, S. F.; Masamune, S. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 239-275. (e) Gennari, C. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 629-660. (f) Bach, T. Angew. Chem, Int. Ed. Engl. 1994, 33, 417. (g) Franklin, A. S.; Paterson, I. Contemp. Org. Synth. 1994, 1, 317-416. (h) Braun, M.; Sacha, H. J. Prakt. Chem. 1993, 335, 653-668. (i) Sawamura, M.; Ito, Y. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: New York, 1993; pp 367-388.
8. For reviews of enantioselective aldol additions see: (a) Evans, D. A.; Nelson, J. V.; Taber, T. R. In Topics in Stereochemistry; Eliel, E. L., Allinger, N. L., Wilen, S. H., Eds.; Wiley Interscience: New York, 1982; Vol. 13, p 1. (b) Heathcock, C. H. In Comprehensive Carbanion Chemistry; Buncel, E., Durst, T., Eds.; Elsevier: New York, 1984; Vol. 5B, p 177. (c) Heathcock, C. H. In Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: New York, 1984; Vol 3, Chapter 2. (d) Kim, B. M.; Williams, S. F.; Masamune, S. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 239-275. (e) Gennari, C. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 629-660. (f) Bach, T. Angew. Chem, Int. Ed. Engl. 1994, 33, 417. (g) Franklin, A. S.; Paterson, I. Contemp. Org. Synth. 1994, 1, 317-416. (h) Braun, M.; Sacha, H. J. Prakt. Chem. 1993, 335, 653-668. (i) Sawamura, M.; Ito, Y. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: New York, 1993; pp 367-388.
9. For reviews of enantioselective aldol additions see: (a) Evans, D. A.; Nelson, J. V.; Taber, T. R. In Topics in Stereochemistry; Eliel, E. L., Allinger, N. L., Wilen, S. H., Eds.; Wiley Interscience: New York, 1982; Vol. 13, p 1. (b) Heathcock, C. H. In Comprehensive Carbanion Chemistry; Buncel, E., Durst, T., Eds.; Elsevier: New York, 1984; Vol. 5B, p 177. (c) Heathcock, C. H. In Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: New York, 1984; Vol 3, Chapter 2. (d) Kim, B. M.; Williams, S. F.; Masamune, S. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 239-275. (e) Gennari, C. In Comprehensive Organic Synthesis. Additions to C-X π Bonds; Heathcock, C. H., Ed.; Pergamon Press: Oxford; 1991; Vol. 2, Part 2, pp 629-660. (f) Bach, T. Angew. Chem, Int. Ed. Engl. 1994, 33, 417. (g) Franklin, A. S.; Paterson, I. Contemp. Org. Synth. 1994, 1, 317-416. (h) Braun, M.; Sacha, H. J. Prakt. Chem. 1993, 335, 653-668. (i) Sawamura, M.; Ito, Y. In Catalytic Asymmetric Synthesis; Ojima, I., Ed.; VCH: New York, 1993; pp 367-388.
10. Denmark, S. E.; Henke, B. R. J. Am. Chem. Soc. 1991, 113, 2177.
11. (a) Mukaiyama, T. Org. React. 1982, 28, 203.
12. (b) Mukaiyama, T.; Murakami, M. Synthesis 1987, 1043.
13. (c) Kobayashi, S.; Uchiro, H.; Shiina, I.; Mukaiyama, T. Tetrahedron 1993, 49, 1761.
14. Denmark, S. E.; Lee, W. J. Org. Chem. 1994, 59, 707.
15. (a) Denmark, S. E.; Coe, D. M.; Pratt, N. E.; Griedel, B. D. J. Org. Chem. 1994, 59, 6161.
16. (b) Kobayashi has pioneered the use of formamides as promoters of this reaction; see: Kobayashi, S.; Nishio, K. J. Org. Chem. 1994, 59, 6620.
17. (a) Nakamura, E.; Kuwajima, I. Chem. Lett. 1983, 59.
18. (b) Nakamura, E.; Kuwajima, I. Tetrahedron Lett. 1983, 24, 3347.
19. (c) Pridgen, L. N.; Abdel-Magid, A.; Lantos, I. Tetrahedron Lett. 1989, 30, 5539.
20. (d) Veronese, A. C.; Gandolfi, V.; Basato, M.; Corain, B. J. Chem. Res. Synop. 1988, 246.
21. (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Raimondi, L. Tetrahedron 1994, 50, 5821.
22. (f) For a general review of the chemistry of tin enolates, see: Shibata, I.; Baba, A. Org. Prep. Proced. Int. 1994, 26, 85.
23. The literature on reactions of trichlorotitanium enolates is vast. Only leading papers containing previous references from representative laboratories are listed: (a) Yamago, S.; Machii, D.; Nakamura, E. J. Org. Chem. 1991, 56, 2098. (b) Harrison, C. R. Tetrahedron Lett. 1987, 28, 4135. (c) Evans, D. A.; Duffy, J. L.; Dart, M. J. Tetrahedron Lett. 1994, 35, 8537. (d) Evans, D. A.; Rieger, D. L.; Bilodeau, M. T.; Urpi, F. J. Am. Chem. Soc. 1991, 113, 1047. (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Ponzini, F.; Raimondi, L. Tetrahedron 1994, 50, 2939. (f) Yan, T.-H.; Hung, A.-W.; Lee, H.-C.; Chang, C-S.; Liu, W.-H. J. Org. Chem. 1995, 60, 3301. (g) Abrahams, I.; Motevalli, M.; Robinson, A. J.; Wyatt, P. B. Tetrahedron 1994, 50, 12755. (h) Pridgen, L. N.; Abdel-Magid, A. F.; Lantos, I.; Shilcrat, S.; Eggleston, D. S. J. Org. Chem. 1993, 58, 5107. (i) Luke, G. P.; Morris, J. J. Org. Chem. 1995, 60, 3013.
24. The literature on reactions of trichlorotitanium enolates is vast. Only leading papers containing previous references from representative laboratories are listed: (a) Yamago, S.; Machii, D.; Nakamura, E. J. Org. Chem. 1991, 56, 2098. (b) Harrison, C. R. Tetrahedron Lett. 1987, 28, 4135. (c) Evans, D. A.; Duffy, J. L.; Dart, M. J. Tetrahedron Lett. 1994, 35, 8537. (d) Evans, D. A.; Rieger, D. L.; Bilodeau, M. T.; Urpi, F. J. Am. Chem. Soc. 1991, 113, 1047. (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Ponzini, F.; Raimondi, L. Tetrahedron 1994, 50, 2939. (f) Yan, T.-H.; Hung, A.-W.; Lee, H.-C.; Chang, C-S.; Liu, W.-H. J. Org. Chem. 1995, 60, 3301. (g) Abrahams, I.; Motevalli, M.; Robinson, A. J.; Wyatt, P. B. Tetrahedron 1994, 50, 12755. (h) Pridgen, L. N.; Abdel-Magid, A. F.; Lantos, I.; Shilcrat, S.; Eggleston, D. S. J. Org. Chem. 1993, 58, 5107. (i) Luke, G. P.; Morris, J. J. Org. Chem. 1995, 60, 3013.
25. The literature on reactions of trichlorotitanium enolates is vast. Only leading papers containing previous references from representative laboratories are listed: (a) Yamago, S.; Machii, D.; Nakamura, E. J. Org. Chem. 1991, 56, 2098. (b) Harrison, C. R. Tetrahedron Lett. 1987, 28, 4135. (c) Evans, D. A.; Duffy, J. L.; Dart, M. J. Tetrahedron Lett. 1994, 35, 8537. (d) Evans, D. A.; Rieger, D. L.; Bilodeau, M. T.; Urpi, F. J. Am. Chem. Soc. 1991, 113, 1047. (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Ponzini, F.; Raimondi, L. Tetrahedron 1994, 50, 2939. (f) Yan, T.-H.; Hung, A.-W.; Lee, H.-C.; Chang, C-S.; Liu, W.-H. J. Org. Chem. 1995, 60, 3301. (g) Abrahams, I.; Motevalli, M.; Robinson, A. J.; Wyatt, P. B. Tetrahedron 1994, 50, 12755. (h) Pridgen, L. N.; Abdel-Magid, A. F.; Lantos, I.; Shilcrat, S.; Eggleston, D. S. J. Org. Chem. 1993, 58, 5107. (i) Luke, G. P.; Morris, J. J. Org. Chem. 1995, 60, 3013.
26. The literature on reactions of trichlorotitanium enolates is vast. Only leading papers containing previous references from representative laboratories are listed: (a) Yamago, S.; Machii, D.; Nakamura, E. J. Org. Chem. 1991, 56, 2098. (b) Harrison, C. R. Tetrahedron Lett. 1987, 28, 4135. (c) Evans, D. A.; Duffy, J. L.; Dart, M. J. Tetrahedron Lett. 1994, 35, 8537. (d) Evans, D. A.; Rieger, D. L.; Bilodeau, M. T.; Urpi, F. J. Am. Chem. Soc. 1991, 113, 1047. (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Ponzini, F.; Raimondi, L. Tetrahedron 1994, 50, 2939. (f) Yan, T.-H.; Hung, A.-W.; Lee, H.-C.; Chang, C-S.; Liu, W.-H. J. Org. Chem. 1995, 60, 3301. (g) Abrahams, I.; Motevalli, M.; Robinson, A. J.; Wyatt, P. B. Tetrahedron 1994, 50, 12755. (h) Pridgen, L. N.; Abdel-Magid, A. F.; Lantos, I.; Shilcrat, S.; Eggleston, D. S. J. Org. Chem. 1993, 58, 5107. (i) Luke, G. P.; Morris, J. J. Org. Chem. 1995, 60, 3013.
27. The literature on reactions of trichlorotitanium enolates is vast. Only leading papers containing previous references from representative laboratories are listed: (a) Yamago, S.; Machii, D.; Nakamura, E. J. Org. Chem. 1991, 56, 2098. (b) Harrison, C. R. Tetrahedron Lett. 1987, 28, 4135. (c) Evans, D. A.; Duffy, J. L.; Dart, M. J. Tetrahedron Lett. 1994, 35, 8537. (d) Evans, D. A.; Rieger, D. L.; Bilodeau, M. T.; Urpi, F. J. Am. Chem. Soc. 1991, 113, 1047. (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Ponzini, F.; Raimondi, L. Tetrahedron 1994, 50, 2939. (f) Yan, T.-H.; Hung, A.-W.; Lee, H.-C.; Chang, C-S.; Liu, W.-H. J. Org. Chem. 1995, 60, 3301. (g) Abrahams, I.; Motevalli, M.; Robinson, A. J.; Wyatt, P. B. Tetrahedron 1994, 50, 12755. (h) Pridgen, L. N.; Abdel-Magid, A. F.; Lantos, I.; Shilcrat, S.; Eggleston, D. S. J. Org. Chem. 1993, 58, 5107. (i) Luke, G. P.; Morris, J. J. Org. Chem. 1995, 60, 3013.
28. The literature on reactions of trichlorotitanium enolates is vast. Only leading papers containing previous references from representative laboratories are listed: (a) Yamago, S.; Machii, D.; Nakamura, E. J. Org. Chem. 1991, 56, 2098. (b) Harrison, C. R. Tetrahedron Lett. 1987, 28, 4135. (c) Evans, D. A.; Duffy, J. L.; Dart, M. J. Tetrahedron Lett. 1994, 35, 8537. (d) Evans, D. A.; Rieger, D. L.; Bilodeau, M. T.; Urpi, F. J. Am. Chem. Soc. 1991, 113, 1047. (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Ponzini, F.; Raimondi, L. Tetrahedron 1994, 50, 2939. (f) Yan, T.-H.; Hung, A.-W.; Lee, H.-C.; Chang, C-S.; Liu, W.-H. J. Org. Chem. 1995, 60, 3301. (g) Abrahams, I.; Motevalli, M.; Robinson, A. J.; Wyatt, P. B. Tetrahedron 1994, 50, 12755. (h) Pridgen, L. N.; Abdel-Magid, A. F.; Lantos, I.; Shilcrat, S.; Eggleston, D. S. J. Org. Chem. 1993, 58, 5107. (i) Luke, G. P.; Morris, J. J. Org. Chem. 1995, 60, 3013.
29. The literature on reactions of trichlorotitanium enolates is vast. Only leading papers containing previous references from representative laboratories are listed: (a) Yamago, S.; Machii, D.; Nakamura, E. J. Org. Chem. 1991, 56, 2098. (b) Harrison, C. R. Tetrahedron Lett. 1987, 28, 4135. (c) Evans, D. A.; Duffy, J. L.; Dart, M. J. Tetrahedron Lett. 1994, 35, 8537. (d) Evans, D. A.; Rieger, D. L.; Bilodeau, M. T.; Urpi, F. J. Am. Chem. Soc. 1991, 113, 1047. (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Ponzini, F.; Raimondi, L. Tetrahedron 1994, 50, 2939. (f) Yan, T.-H.; Hung, A.-W.; Lee, H.-C.; Chang, C-S.; Liu, W.-H. J. Org. Chem. 1995, 60, 3301. (g) Abrahams, I.; Motevalli, M.; Robinson, A. J.; Wyatt, P. B. Tetrahedron 1994, 50, 12755. (h) Pridgen, L. N.; Abdel-Magid, A. F.; Lantos, I.; Shilcrat, S.; Eggleston, D. S. J. Org. Chem. 1993, 58, 5107. (i) Luke, G. P.; Morris, J. J. Org. Chem. 1995, 60, 3013.
30. The literature on reactions of trichlorotitanium enolates is vast. Only leading papers containing previous references from representative laboratories are listed: (a) Yamago, S.; Machii, D.; Nakamura, E. J. Org. Chem. 1991, 56, 2098. (b) Harrison, C. R. Tetrahedron Lett. 1987, 28, 4135. (c) Evans, D. A.; Duffy, J. L.; Dart, M. J. Tetrahedron Lett. 1994, 35, 8537. (d) Evans, D. A.; Rieger, D. L.; Bilodeau, M. T.; Urpi, F. J. Am. Chem. Soc. 1991, 113, 1047. (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Ponzini, F.; Raimondi, L. Tetrahedron 1994, 50, 2939. (f) Yan, T.-H.; Hung, A.-W.; Lee, H.-C.; Chang, C-S.; Liu, W.-H. J. Org. Chem. 1995, 60, 3301. (g) Abrahams, I.; Motevalli, M.; Robinson, A. J.; Wyatt, P. B. Tetrahedron 1994, 50, 12755. (h) Pridgen, L. N.; Abdel-Magid, A. F.; Lantos, I.; Shilcrat, S.; Eggleston, D. S. J. Org. Chem. 1993, 58, 5107. (i) Luke, G. P.; Morris, J. J. Org. Chem. 1995, 60, 3013.
31. The literature on reactions of trichlorotitanium enolates is vast. Only leading papers containing previous references from representative laboratories are listed: (a) Yamago, S.; Machii, D.; Nakamura, E. J. Org. Chem. 1991, 56, 2098. (b) Harrison, C. R. Tetrahedron Lett. 1987, 28, 4135. (c) Evans, D. A.; Duffy, J. L.; Dart, M. J. Tetrahedron Lett. 1994, 35, 8537. (d) Evans, D. A.; Rieger, D. L.; Bilodeau, M. T.; Urpi, F. J. Am. Chem. Soc. 1991, 113, 1047. (e) Annunziata, R.; Benaglia, M.; Cinquini, M.; Cozzi, F.; Ponzini, F.; Raimondi, L. Tetrahedron 1994, 50, 2939. (f) Yan, T.-H.; Hung, A.-W.; Lee, H.-C.; Chang, C-S.; Liu, W.-H. J. Org. Chem. 1995, 60, 3301. (g) Abrahams, I.; Motevalli, M.; Robinson, A. J.; Wyatt, P. B. Tetrahedron 1994, 50, 12755. (h) Pridgen, L. N.; Abdel-Magid, A. F.; Lantos, I.; Shilcrat, S.; Eggleston, D. S. J. Org. Chem. 1993, 58, 5107. (i) Luke, G. P.; Morris, J. J. Org. Chem. 1995, 60, 3013.
32. (a) Burlacnenko, G. S.; Khasapov, B. N.; Petrovskaya, L. I.; Baukov, Yu, I.; Lutsenko, I. F. J. Gen. Chem. USSR (Engl. Transl.) 1966, 36, 532.
33. (b) Lutsenko, I. F.; Baukov, Yu, I.; Burlachenko, G. S.; Khasapov, B. N. J. Organomet. Chem. 1966, 5, 20.
34. (c) Burlachenko, G. S.; Baukov, Yu, I.; Dzherayan, T. G.; Lutsenko, I. F. J. Gen. Chem. USSR (Engl. Transl.) 1975, 45, 73.
35. (d) Baukov, Yu. I.; Lutsenko, I. F. Moscow Univ. Chem. Bull. (Engl. Transi.) 1970, 25, 72.
36. (e) Ponomarev, S. V.; Baukov, Yu, I.; Dudukina, O. V.; Petrosyan, I. V.; Petrovskaya, L. I. J. Gen. Chem. USSR (Engl. Transl.) 1967, 37, 2092.
37. (f) Benkeser, R. A.; Smith, W. E. J. Am. Chem. Soc. 1968, 90, 5307.
38. (g) Burlachenko, G. S.; Baukov, Yu, I.; Lutsenko, I. F. J. Gen. Chem. USSR (Engl. Transl.) 1970, 40, 88.
39. For reports on the preparation of other chlorosilyl enolates, see: (a) Walkup, R. D. Tetrahedron Lett. 1987, 28, 511. (b) Walkup, R. D.; Obeyesekere, N. U., Kane, R. R. Chem. Lett. 1990, 1055. (c) Kaye, P. T.; Learmonth, R. A.; Ravindran, S. S. Synth. Commun. 1993, 23, 437.
40. For reports on the preparation of other chlorosilyl enolates, see: (a) Walkup, R. D. Tetrahedron Lett. 1987, 28, 511. (b) Walkup, R. D.; Obeyesekere, N. U., Kane, R. R. Chem. Lett. 1990, 1055. (c) Kaye, P. T.; Learmonth, R. A.; Ravindran, S. S. Synth. Commun. 1993, 23, 437.
41. For reports on the preparation of other chlorosilyl enolates, see: (a) Walkup, R. D. Tetrahedron Lett. 1987, 28, 511. (b) Walkup, R. D.; Obeyesekere, N. U., Kane, R. R. Chem. Lett. 1990, 1055. (c) Kaye, P. T.; Learmonth, R. A.; Ravindran, S. S. Synth. Commun. 1993, 23, 437.
42. Zapata, A.; Acuña A. C. Synth. Commun. 1984, 14, 27.
43. All compounds described herein were fully characterized by spectroscopic and analytical methods. See the supporting information.
44. (a) Pereyre, M.; Bellegarde, B.; Mendelsohn, J.; Valade, J. J. Organomet. Chem. 1968, 11, 97.
45. (b) Yasuda, M.; Katoh, Y.; Shibata, I.; Baba, A.; Matsuda, H.; Sonoda, N. J. Org. Chem. 1994, 59, 4386.
46. The absolute configuration of (-)-anti-8a has been determined to be (2R, I'S) by X-ray analysis of the 4-bromobenzoate derivative. This will be described in a full account.