Asymmetric Synthesis of β-Amino Acids by Addition of Chiral Enolates to <i>N</i>-Acyloxyiminium Ions and Application for Synthesis of Optically Active 5-Substituted 8-Methylindolizidines
作者:Toru Kawakami、Hiroaki Ohtake、Hiroaki Arakawa、Takahiro Okachi、Yasushi Imada、Shun-Ichi Murahashi
DOI:10.1021/ol9905755
日期:1999.7.1
[GRAPHICS]N-Acyloxyiminium species generated from nitrones with acyl halides are highly reactive and can undergo reaction with soft nucleophiles such as enolates. Optically active beta-amino acid derivatives can be prepared using chiral enolates bearing chiral auxiliary. The usefulness of the present method is demonstrated by the enantioselective synthesis of (SR,8R,8aS)-5-cyano-8-methylindolizidine ((-)-7), which is a common key intermediate for 5-substituted 8-methylindolizidines.