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

摘要

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: <IMAGE> (I) 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.