Sterically Controlled Syntheses of Optically Active Organic Compounds. XIV. Syntheses of Dipeptides from N-(α-Ketoacyl)-α-amino Acid Esters

Abstract

Abstract Optically active α-amino acids were synthesized from azomethines of N-α-ketoacyl-amino acid esters by catalytic hydrogenation. When optically active (S)-alanine was used, (R)-amino acyl-(S)-alanine ester was obtained. When alkyl groups of optically active (S)-amino acids in the N-α-ketoacyl-amino acid esters were larger than ethyl group, the configurations of newly formed amino acids were found to be (S). From these results possible steric courses of the asymmetric syntheses are discussed.