Towards the stereoselective synthesis of alpha-methylated (2S,3aS,7aS)-octahydroindole-2-carboxylic acid

Tetrahedron Asymmetry. 2008 Dec 12;19(24):2763-2766. doi: 10.1016/j.tetasy.2008.11.030.

Abstract

A high yielding and remarkably stereoselective alpha-methylation reaction of the (2S,3aS,7aS) stereoisomer of octahydroindole-2-carboxylic acid, (S,S,S)-Oic, suitably protected is described. The severe steric hindrance imposed by the fused cyclohexane ring, which prevents the application of Seebach's self-reproduction of chirality methodology, accounts for the formation of (S,S,S)-(alphaMe)Oic with high selectivity and retention of configuration.