Patent ID: 7109004

Claim:
A process for preparing (R)-hydroxy ester (II) from alpha-keto ester I comprising adding the alpha-keto ester I to a mixture comprising a ketoreductase enzyme and non-ketoreductase enzyme components, wherein R 1 is C 1-4 alkyl; and R 2 is selected from the group consisting of C 1-8 alkyl, C 1-8 alkyl, substituted with C 3-7 cycloalkyl, aryl, and a 5- to 7-membered saturated or unsaturated heterocyclic ring, wherein the ketoreductase enzyme has a molecular weight between 36000 and 38000, and wherein the ketoreductase enzyme has an N-terminal amino acid sequence selected from the group of sequences consisting of (SEQ. ID NO. 1) Ala-Ale-Pro-Asp-Asn-Ala-Val-Leu-Glu-Gly-Ser-Leu- Val-Lys-Val-Thr-Gly-Ala-Asn-Gly (SEQ. ID NO. 4) Met-Ala-Ile-Pro-Asp-Asn-Ala-Val-Leu-Glu-Gly-Ser- Leu-Val-Lys-Val-Thr-Gly-Ala-Asn-Gly, and (SEQ ID NO. 2) Met-Ala-Lys-Ile-Asp-Asn-Ala-Val-Leu-Pro-Glu-Gly- Ser-Leu-Val-Leu-Val-Thr-Gly-Ala-Asn-Gly.