Aluminum chloride-mediated kinetic resolution of racemic gamma-substituted-gamma-lactones

Abstract

Preparation of chiral gamma-substituted-gamma-lactones (1) through kinetic resolution is described. (S)-(-)-1-Phenylethylamine (2) in the presence of anhydrous AlCl(3) shows satisfactory levels of enantioselection in reaction with racemic gamma-substituted-gamma-lactones 1, where (R)-1 remains unreacted, while (S)-1 is enantioselectively converted to the ring-opened amide (S,S)-4. The enantiopurity of (R)-(+)- gamma-substituted gamma-lactones recovered ranges from 62-98% ee.