Optical Resolution and Stereochemistry of γ-Hydroxyglutamic Acid

Abstract

Abstract Four optical isomers of γ-hydroxyglutamic acid were prepared in pure states by optical resolution of two racemic diastereoisomers through brucine salt of N-benzyloxycarbonyl amino acid or strychnine salt of N-benzoyl derivative. Configurations of α- and γ-asymmetric carbon atoms of these isomers were estimated from contribution to molecular rotation and character of taste exhibition. These determinations were confirmed by chemical degradations to aspartic acid and malic diamide of the definite configurations. Cyclization of each racemic diastereomer to either lactone or lactam was also investigated.