Dynamic Kinetic Resolution of α-Amino Acid Esters

Abstract

A useful transformation from racemic α-amino esters to enantiomerically pure amino acids is described. The amino esters are racemized in the presence of catalytic amounts of sali­cylaldehyde 1 via the deprotonation of an imine intermediate. The combination of this racemization with an ester hydrolysis catalyzed by alcalase®, an endoproteinase of the serine type, leads to the corresponding acids in high yields and high enantioselectivities. Five different amino acids were synthesized in high optical purities with the developed method.