Enantioselective intramolecular cyclizations of prochiral cyclohexanones using chiral lithium amide bases

Chemical Communications

Volumn , Issue 21, 1998, Pages 2357-2358

  Kropf, Jeffrey E ^a   Weinreb, Steven M ^a  

^a PENNSYLVANIA STATE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0003001008     PISSN: 13597345     EISSN: None     Source Type: Journal    
DOI: 10.1039/a807052k     Document Type: Article

References (23)

1. (a) For reviews, see: K. Koga, J. Synth. Org. Chem. Jpn., 1990, 48, 463;
2. (b) P. J. Cox and N. S. Simpkins, Tetrahedron: Asymmetry, 1991, 2, 1;
3. (c) K. Koga, Pure Appl. Chem., 1994, 66, 1487;
4. (d) K. Koga and M. Shindo, J. Synth. Org. Chem. Jpn., 1995, 53, 1021;
5. (e) N. S. Simpkins, Pure Appl Chem., 1996, 68,691;
6. (f) P. O'Brien, J. Chem. Soc., Perkin Trans, 1, 1998, 1439.
7. The large majority of the work on enantioselective deprotonation of prochiral ketones using chiral lithium amide bases involves trapping the resulting enolates as silyl enol ethers: K. Aoki and K. Koga, Tetrahedron Lett., 1997, 38, 2505;
8. R. Shirai, D. Sato, K. Aoki, M. Tanaka, H. Kawasaki and K. Koga, Tetrahedron, 1997, 53, 5963;
9. H. Chatani, M. Nakajima, H. Kawasaki and K. Koga, Heterocycles, 1997, 46, 53;
10. K. Aoki, K. Tomioka, H. Noguchi and K. Koga, Tetrahedron, 1997, 53, 13 641.
11. In addition, chiral lithium amide bases have beeen successfully used for the enantioselective rearrangement of epoxides (ref. 4), aromatic and benzylic functionalization of aryl chromium complexes (ref. 5), as well as the asymmetric [2,3]-Wittig rearrangement (ref. 6).
12. M. Asami, J. Synth. Org. Chem. Jpn., 1996, 54, 188;
13. D. M. Hodgson, A. R. Gibbs and G. P. Lee, Tetrahedron, 1996, 52, 14 361.
14. R. A. Ewin, A. M. MacLeod, D. A. Price, N. S. Simpkins and A. P. Watt, J. Chem Soc., Perkin Trans, 1, 1997, 401.
15. S. E. Gibson, P. Ham and G. R. Jefferson, Chem. Commun., 1998, 123.
16. Iodo ketone 1 was synthesized from 4-(3-chloropropyl)cyclohexanone (cf. A. G. Schultz and J. P. Dittami, J. Org. Chem., 1984, 49, 2615) by a Finkelstein reaction (NaI, acetone, 90%).
17. 2 (60%).
18. The amine is available commercially as the hydrochloride salt.
19. R. Shirai, K. Aoki, D. Sato, H.-D. Kim, M. Murakata, T. Yasukata and K. Koga, Chem. Pharm. Bull., 1994, 42, 690.
20. K. Bambridge, M. J. Begley and N. S. Simpkins, Tetrahedron Lett., 1994, 35, 3391.
21. The absolute stereochemistry of bicyclic ketones 3 and 4 was determined using the CD Octant rule. For a good discussion, see: E. L. Eliel and S. H. Wilen, Stereochemistry of Organic Compounds, Wiley, New York, 1994, p. 1022.
22. Racemic ketone 3 is commercially available. Racemic 4: E. N. Marvell, D. Sturmer and C. Rowell, Tetrahedron, 1966, 22, 861.
23. K. Sugasawa, M. Shindo, H. Noguchi and K. Koga, Tetrahedron Lett., 1996, 37, 7377.