Double stereodifferentiating aldol reactions of (E) and (Z) lithium enolates. Model reactions for polypropionate assemblage

Tetrahedron Letters

Volumn 37, Issue 12, 1996, Pages 1957-1960

  Evans, David A ^a   Yang, Michael G ^a   Dart, Michael J ^a   Duffy, Joseph L ^a  

^a HARVARD UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

ALDEHYDE; KETONE; POLYOL;

ARTICLE; DRUG SYNTHESIS; ENANTIOMER; REACTION ANALYSIS; STEREOCHEMISTRY;

EID: 0029926858     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/0040-4039(96)00178-5     Document Type: Article

References (30)

1. (a) Evans, D. A.; Nelson, J. V.; Taber, T. Top. Stereochem. 1982, 13, 1-115.
2. (b) Heathcock, C. H. In Asymmetric Synthesis; Monison, J. D., Ed.; Academic Press: New York, 1983; Vol. 3, Ch. 2, pp 111-212.
3. (c) Paterson, I. in Comprehensive Organic Synthesis: Additions to C-X π-Bonds Part 2; Trost, B. M.; Fleming, I.; Heathcock, C. Eds.; Pergamon Press; NY, 1991; Ch 1.9.
4. Titanium enolates: (a) Evans, D. A.; Rieger, D. L.; Bilodeau, M. T.; Urpi, F. J. Am. Chem. Soc. 1991, 113, 1047-1049.
5. (b) Evans, D. A.; Dart, M. J.; Duffy, J. L.; Rieger, D. L. J. Am. Chem. Soc., 1995, 117, 9073-9074.
6. (Z) Boron enolates: (c) Evans, D. A.; Duffy, J. L. unpublished results, Chemistry Department, Harvard University.
7. See also: (d) Paterson, I.; McClure, C. K. Tetrahedron Lett. 1987, 28, 1229-1232.
8. (Z) Lithium enolates: (e) McCarthy, P.; Kageyama, M. J. Org. Chem. 1987, 52, 4681-4686.
9. (a) Evans, D. A.; Ng., H. P.; Clark, J. S.; Rieger, D. L. Tetrahedron 1992, 48, 2127-2142.
10. (b) ref 2(b).
11. For a complementary double stereodifferentiating anti aldol reaction, see: (c) Paterson, I.; Perkins, M. V. J. Am. Chem. Soc. 1993, 115, 1608-1610.
12. The chiral lithium enolates 1a and 1b were prepared by the indicated methods in ≥ 92:8 geometric purity as determined by capillary GC analysis of the corresponding enolsilanes.
13. Masamune, S.; Ellingboe, J. W.; Choy, W. J. Am. Chem. Soc. 1982, 104, 5526-5528.
14. Hall, P. L.; Gilchrist, J. H.; Collum, D. B. J. Am. Chem. Soc. 1991, 113, 9571-9574.
15. The reaction illustrated in eq 14 afforded an identical diastereomeric product mixture after 30 sec or 30 min at -78 °C, however warming to -30 °C for 30 min produced a 1:1:1 mixture of diastereomers. For lithium aldol equilibration examples see: (a) Heathcock, C. H.; Buse, C. T.; Kleschick, W. A.; Pirrung, M. C.; Sohn, J. E.; Lampe. J. J. Org. Chem. 1980, 45, 1066-1081.
16. (b) Abdel-Magid, A. F.; Pridgen, L. N.; Eggleston, D. S.; Lantos, I. J. Am. Chem. Soc. 1986, 108, 4595-4602.
17. (c) Gustin, D. J.; VanNieuwenhze, M. S.; Roush, W. R. Tetrahedron Lett. 1995, 36, 3447-3450.
18. Diastereoselectivity was determined by capillary GC analysis of the silylated or acetylated product mixtures prior to purification. The yields of all reactions were 63-86%. Stereochemical proofs were carried out on each product as in ref 2(b).
19. Roush, W. R. J. Org. Chem. 1991, 56, 4151-4157 and references cited therein.
20. (a) Evans, D. A.; Duffy, J. L.; Dart, M. J. Tetrahedron Lett. 1994, 35, 8537-8540.
21. (b) Evans D. A.; Dart, M. J.; Duffy, J. L.; Yang, M. G.; Livingston, A. B. J. Am. Chem. Soc. 1995, 117, 6619-6620.
22. (a) Das, G.; Thornton, E. R. J. Am. Chem. Soc. 1993, 115, 1302-1312.
23. (b) Heathcock, C. H.; Young, S. D.; Hagen, J. P.; Pirrung, M. C.; White, C. T.; VanDerveer, D. J. Org. Chem. 1980, 45, 3846-3856.
24. Masamune, S.; Choy, W.; Peterson, J. S.; Sita, L. R. Angew Chem. Int. Ed. Engl. 1985, 24, 1-30.
25. The enolate β stereocenter may represent a fourth stereocontrol element. However, the relative configuration of the enolate β-stereocenter has been held constant for the present study.
26. For double asymmetric lithium aldol reactions see: (a) Martin, S. F.; Lee, W. C.; Pacofsky, G. J.; Gist, R. P.; Mulhern, T. A. J. Am. Chem. Soc. 1994, 116, 4674-4688.
27. (b) Martin, S. F.; Lee, W-C. Tetrahedron Lett. 1993, 34, 2711-2714.
28. (c) Sviridov, A. F.; Ermolenko, M. S.; Yashunsky, D. V.; Kochetkov, N. K. Tetrahedron. 1991, 47, 2317-2336.
29. (d) ref 7(c).
30. (e) ref 12.