Ring-opening of oxazolines derived from l-serine: a short and efficient stereoselective synthesis of all four diastereomers of 3-mercaptoaspartic acid derivatives

Facile methods are described for accessing four diastereomerically pure 3-mercaptoaspartic acid derivative from l-aspartic acid. In our synthesis, ring-opening reactions of oxazoline-4,5-dicarboxylate with thiolacetic acid as well as the stereochemical interconversion of both α- and β-configuration via oxazoline chemistry were utilized as key steps.