Synlett 1997; 1997(8): 956-958
DOI: 10.1055/s-1997-937
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Diastereoselective Protonation of Chiral Enolate with Chiral Imides

Akira Yanagisawa, Tsuyoshi Watanabe, Tetsuo Kikuchi, Takeshi Kuribayashi, Hisashi Yamamoto*
  • *Graduate School of Engineering, Nagoya University, CREST, Japan, Chikusa, Nagoya 464-01, Japan
Further Information

Publication History

Publication Date:
31 December 2000 (online)

Described herein is a diastereoselective protonation of a chiral enolate with chiral imides. When the lithium enolate of (-)-menthone was protonated by (S,S)-imide 1 or (R)-imide 9, cis-ketone 7 was the major product formed (trans-product 6:cis-product 7 = 26:74 ~19:81). In contrast, a high trans-selectivity (6:7 = 93:7 ~ 97:3) was obtained for the reaction with (R,R)-imide 8 or (S)-imide 10. The catalytic process of this diastereoselective protonation has been realized using a catalytic amount of these chiral imides and stoichiometric amount of an achiral proton source.