Asymmetric Aldol Reactions. A New Camphor-Derived Chiral Auxiliary Giving Highly Stereoselective Aldol Reactions of both Lithium and Titanium(IV) Enolates

Journal of the American Chemical Society

Volumn 113, Issue 4, 1991, Pages 1299-1308

  Bonner, Mary Pat ^a   Thornton, Edward R ^a  

^a UNIVERSITY OF PENNSYLVANIA   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0000318952     PISSN: 00027863     EISSN: 15205126     Source Type: Journal    
DOI: 10.1021/ja00004a034     Document Type: Article

References (59)

1. Masamune, S.; Choy, W.; Kerdesky, F. A. J.; Imperiali, B. J. Am. Chem. Soc. 1981, 103, 1566–1568.
2. Evans, D. A.; Bartroli, J.; Shih, T. L. J. Am. Chem. Soc. 1981, 103, 2127–2129.
3. Evans, D. A.; Nelson, J, V.; Taber, T. R. Top. Stereochem. 1982, 13, 1–115.
4. Masamune, S.; Choy, W.; Petersen, J. S.; Sita, L. R. Angew. Chem., Ini. Ed. Engl. 1985, 24, 1–30.
5. Corey, E. J.; Kim, S. S. J. Am. Chem. Soc. 1990, 112, 4976–4977.
6. Nerz-Stormes, M.; Thornton, E. R. Tetrahedron Lett. 1986, 27, 897–900.
7. Siegel, C.; Thornton, E. R. Tetrahedron Lett. 1986, 27, 457–460.
8. Siegel, C.; Thornton, E. R. J. Am. Chem. Soc. 1989, 111, 5722–5728.
9. Evans, D. A.; Clark, J. S.; Metternich, R.; Novack, V. J.; Sheppard, G. S. J. Am. Chem. Soc. 1990, 112, 866–868.
10. Duthaler, R. O.; Herold. P.; Wyler-Helfer, S.; Riediker, M. Helv. Chim. Acta 1990, 73, 659–673.
11. Duthaler, R. O.; Herold, P.; Lottenbach, W.; Oertle, K.; Riediker, M. Angew. Chem., Int. Ed. Engl. 1989, 28, 495–497.
12. Evans, D. A.; Bender, S. L.; Morris, J. J. Am. Chem. Soc. 1988, 110, 2506–2526.
13. Evans, D. A.; Weber, A. E. J. Am. Chem. Soc. 1986, 108, 6757–6761.
14. Evans, D. A.; Sjogren, E. B.; Weber, A. E.; Conn, R. E. Tetrahedron Lett. 1987, 28, 39–42.
15. Evans, D. A.; Britton, T. C. J. Am. Chem. Soc. 1987,109, 6881–6883.
16. Evans, D. A.; Ellman, J. A. J. Am. Chem. Soc. 1989, 111, 1063–1072.
17. Reetz, M. T. Organotitanium Reagents in Organic Synthesis; Springer-Verlag: Berlin, 1986.
18. Oppolzer, W. Tetrahedron 1987, 43, 1969–2004.
19. Oppolzer, W.; Blagg, J.; Rodriguez, I.; Walther, E. J. Am. Chem. Soc. 1990, 112, 2767–2772.
20. An experiment with the tert-butyldimethylsilyl-trapped enolate of the N-(α-chloroacetyl)valine-derived oxazolidinone indicated, by the absence of a 1H NOE between the olefinic proton and the silylmethyl groups, a Z configuration21 However, absence of an NOE cannot be considered (and was not claimed to be) conclusive. Conclusive assignment of Z configuration to the silyl-trapped enolate XcC(=O)CHMeC(OTMS)=CHMe, where Xc is a chiral N-oxazolidinone group (which is not, however, the enolate of an N-acyloxazolidinone), was made through a 1H NMR NOE study.9
21. Abdel-Magid, A.; Pridgen, L. N.; Eggleston, D. S.; Lantos, I. J. Am. Chem. Soc. 1986, 108, 4595–4602.
22. Arvanitis, A. Ph.D. Dissertation in Chemistry, Boston College, Boston, 1984.
23. Kelly, T. R.; Arvanitis, A. Tetrahedron Lett. 1984, 25, 39–42.
24. Liu, J. H. Angew. Makromol. Chem. 1987, 155, 83–92.
25. Chittenden, R. A.; Cooper, G. H. J. Chem. Soc. C 1970, 49–54.
26. Pauling, v. H. Helv. Chim. Acta 1975, 58, 1781–1798.
27. In their publications for the synthesis of amino alcohol 4,22–26 other workers utilized as their initial step the procedure of Forster and Rao (Forster, M. O.; Rao, K. A. N. J. Chem. Soc. 1926, 2670–2675) for the α-oximation of camphor with Na metal and isoamyl nitrite to provide oxime 2. When we carried out this reaction on various scales (up to 228 mmol of camphor), we obtained a 3:2 mixture of syn and anti oximes 2 in yields ranging from 26 to 40%. Despite extensive modification of the originally published procedure, the yields remained disappointingly low. We found that a much higher yield (86%) of a-oxime 2 could be realized by the regioselective monooximation of camphorquinone under mild conditions.
28. Beckett, A. H.; Lan, N. T.; McDonough, G. R. Tetrahedron 1969, 25, 5689–5692.
29. Newman, M. S.; Kutner, A. J. Am. Chem. Soc. 1951, 73, 4199–4204.
30. An excess of ClTi(OCH(CH3)2)3 (3 molar equiv) was used since it had been previously demonstrated that the stereoselectivities of Ti-mediated aldol reactions could be dramatically improved by addition of an excess of the titanium reagent.6–8 It was proposed that the lower selectivity observed with 1 equiv of ClTi(OCH(CH3)2)3 might arise from interference by a lithium titanium ate enolate complex [Li+C=COTi−Cl(OCH(CH3)2)3].
31. X-ray crystal structure data for compounds 7, 9, 18, 19, and 21 are available as supplementary material.
32. Heathcock, C. H. In Asymmetric Synthesis, Morrison, J. D., Ed.; Academic Press; Orlando, FL, 1984; Vol. 3, pp 111–212.
33. Reference 3, pp 5–7.
34. Heathcock, C. H. In Current Trends in Organic Synthesis, Nozaki, H., Ed.; Pergamon Press: Oxford, 1983; pp 27–43.
35. Evans, D. A.; Britton, T. C.; Ellman, J. A. Tetrahedron Lett. 1987, 28, 6141–6144.
36. Heathcock, C. H.; Pirrung, M. C.; Montgomery, S. H.; Lampe, J. Tetrahedron 1981, 37, 4087–4095.
37. Webber, S. E. Ph.D. Dissertation in Chemistry, University of Pennsylvania, Philadelphia, PA, 1986.
38. Reference 32, p 191.
39. Both enantiomers can be prepared by the method of Heathcock: Takai, K.; Heathcock, C. H. J. Org. Chem. 1985, 50, 3247–3251.
40. The absolute configuration for 17 was assigned by comparison of the corresponding β-hydroxy acid (13f) to the acid obtained from the hydrolysis of adduct 18 (13g). Since the absolute configuration of adduct 18 was confirmed through X-ray analysis, the enantiomeric relationship of acids 13f and 13g (established by the fact that their 1H NMR spectra were identical) provided a rigorous assignment of absolute configuration for 17. [13f and 13g cannot be identical, since (a) they are formed from aldehydes (R)-16 and (S)-16 of opposite configurations and (b), in any case, their identity requires that 17 and 18 also be identical, which they are not.]
41. Dubois, J. E.; Fellman, P. Tetrahedron Lett. 1975, 16, 1225–1228.
42. Heathcock, C. H.; Buse, C. T.; Kleschick, W. A.; Pirrung, M. C.; Sohn, J. E.; Lampe, J. J. Org. Chem. 1980, 45, 1066–1081.
43. Zimmerman, H. E.; Traxler, M. D. J. Am. Chem. Soc. 1957. 79. 1920–1923.
44. Li, Y.; Paddon-Row, M. N.; Houk, K. N. J. Org. Chem. 1990. 55, 481–493.
45. Leung-Toung, R.; Tidwell, T. T. J. Am. Chem. Soc. 1990. 112, 042–1048.
46. Bernardi, A.; Capelli, A. M.; Gennari, C.; Goodman, J. M.; Paterson, I. J. Org. Chem. 1990. 55. 3576–3581.
47. Denmark, S. E.; Henke, B. R. J. Am. Chem. Soc. 1989, 111. 8032–8034.
48. Nguyên, Trong Anh; Bui Tho Thanh. Nouv. J. Chim 1986. 10. 681–683.
49. Das, G.; Thornton, E. R. J. Am. Chem. Soc. 1990, 112, 5360–5362.
50. Cornforth, J. W.; Cornforth, R. H.; Mathew, K. K. J. Chem. Soc. 1959, 112–127.
51. Nguyên, Trong Anh. Top. Curr. Chem. 1980, 88, 145–162.
52. Seebach, D. Angew. Chem., Ini. Ed. Engl. 1988, 27, 1624–1654.
53. The aldol reaction of acyloxazolidinone 6 with cyclohexanecarboxaldehyde always afforded an oil as the crude product mixture, which did not solidify even upon trituration with hexane.
54. Perrin, D. D.; Armarego, W, L. F.; Perrin, D. R. Purification of Laboratory Chemicals, 2nd ed.; Pergamon: Oxford, 1980.
55. Still, W. C.; Kahn, M.; Mitra, A. J. Org. Chem. 1978, 43, 2923–2925.
56. The optical rotation of 2, +178° (c 3.5, CH2Cl2), was nearly identical with the value reported by Liu24 +179° (c 0.22, CHCl3). A higher specific rotation value, +231° (c 1.0, CH2Cl2), was measured for the material prepared according to the procedure of Forster and Rao.27 This product existed as a 3:2 mixture of anti and syn oximes, and the product obtained by the monooximation of camphorquinone existed as a 1:5 mixture of anti and syn oximes (anti/syn assignments not certain).
57. The 3 value (ppm) and coupling constant (Hz) for the carbinol proton of erythro-3-hydroxy-2,4,4-trimethylpentanoic acid were reported: 1H NMR (CDCl3, 60 MHz) 3.62 (1 H, d, J = 3). Pirrung, M. C. Ph.D. Dissertation in Chemistry, University of California, Berkeley, 1980, p 195.
58. The specific rotation for (2R,3S)-3-hydroxy-2,4-dimethylpentanoic acid (the enantiomer of 13c) was reported to be +9.30° (c 2.56, CH2Cl2): McGee, L. R. Ph.D. Dissertation in Chemistry, California Institute of Technology, 1982, p 114.
59. Mancuso, A. J.; Huang, S.-L.; Swern, D. J. Org. Chem. 1978, 43, 2480–2482.