Glutamic acid dehydrogenase, optical

L-6-Hydroxynorleucine, a different key chiral intermediate used for synthesis of the vasopeptidase inhibitor Omapatrilat (Vanlev ), was prepared in 89% yield and > 99% optical purity by reductive amination of 2-keto-6-hydroxyhexanoic acid using glutamate dehydrogenase from beefliver (Hanson, 1999) (Figure 13.22). In an alternative process, racemic 6-hydroxynorleucine produced by hydrolysis of 5-(4-hydroxybutyl)hydantoin was treated with D-amino acid oxidase to prepare a mixture containing 2-keto-6-hydroxyhexanoic acid and L-6-hydroxynorleucine followed by the reductive amination procedure to convert the mixture entirely to L-6-hydroxynorleucine, with yields of 91-97% and optical purities of > 99%. 

---