Preparation of Optically Pure tert‐Leucine by Penicillin G Acylase‐Catalyzed Resolution

Abstract Penicillin G acylase, from Kluyvera citrophila, was used in kinetic resolution of DL‐ tert‐leucine. N‐phenylacetylated‐DL‐tert‐leucine, chemically synthesized from DL‐ tert‐leucine, was enantioselctively hydrolyzed by penicillin G acylase to obtain L‐tert‐leucine, D‐ tert‐leucine was prepared by acid‐catalyzed hydrolysis of the remaining substrate. The total yields of D‐ tert‐leucine and L‐tert‐leucine are 80.6% and 83.1%, respectively. The enantiomeric excess of the two products, D‐ tert‐leucine and L‐tert‐leucine, are 98.5% and 99%. This is a practical way for the preparation of D‐ tert‐leucine and L‐tert‐leucine.