<i>threo</i>- and <i>erythro</i>- β-Hydroxy-<scp>DL</scp>-aspartic acids

Abstract

An improved procedure for the synthesis of threo- and erythro-β-hydroxy-DL-aspartic acids is described. An nuclear magnetic resonance study of both diastereomers indicated that the threo isomer exists primarily as the conformer having anti carboxyl groups while the erythro compound prefers a conformation with gauche carboxyl functions. Possible reasons for this anomaly are presented.