Process for the preparation of a free L .alpha.-amino acid

Abstract

This invention relates to a process for the preparation of free L .alpha.-amino acids by the complete conversion of their D antipodes taken individually or possibly in racemic mixtures. The process according to the present invention is characterized in that the D antipodes of an ester of said .alpha.-amino acid is racemized in the presence of a chemical catalyst formed by at least one aromatic aldehyde corresponding to the general formula: ##STR1## wherein: Ar represents an aromatic ring optionally containing a heteroatom, such as nitrogen, and B represents a basic function, to produce a mixture in dynamic equilibrium of the two forms D and L of said ester, the ester which is present in the L form is hydrolyzed enzymatically and irreversibly to produce the corresponding stereostable L .alpha.-amino acid, said stages of chemical racemization and of enzymatic hydrolysis being carried out under identical reaction conditions, and the free L .alpha.-amino acid is recovered.

Dependencies are inferred from the claim text.