RACEMIC SYNTHESIS AND ENANTIOMERIC CONVERSION OF [1-C-13] VALINE

A Strecker synthesis of isobutyraldehyde, (KCN)-C-13 and ammonia produ ced D,L-[1-C-13) valine in 83% yield. This racemic mixture was then co nverted to the L-form via a D-amino acid oxidase - branched amino acid aminotransferase system in an overall yield of 75% based on (KCN)-C-1 3. Given the generality of the Strecker synthesis as well as the broad substrate specificity of the oxidase and aminotransferase enzymes, it is anticipated that this procedure will be comparably efficient for m ost standard aliphatic and aromatic amino acids.