Enzymatic synthesis of L-6-hydroxynorleucine

L-6-Hydroxynorleucine, a key chiral intermediate used for synthesis of a va sopeptidase inhibitor, was prepared in 89% yield and > 99% optical purity b y reductive amination of 2-keto-6-hydroxyhexanoic acid using glutamate dehy drogenase from beef liver, In an alternate process, racemic 6-hydroxynorleu cine produced by hydrolysis of 5-(4-hydroxybutyl)hydantoin was treated with D-annino acid oxidase to prepare a mixture containing 2-keto-6-hydroxyhexa noic acid and L-6-hydroxynorleucine followed by the reductive amination pro cedure to convert the mixture entirely to L-6-hydroxynorleucine, with yield s of 91 to 97% and optical purities of >99%. (C) 1999 Elsevier Science Ltd. All rights reserved.