Patent ID: 8338146

Claim:
A process for preparing an optically active alcohol of formula Ia, in which R 1 and R 2 independently are alkyl, alkenyl, aryl, or alkylaryl groups, each of which may be substituted one or more times by alkyl, halogen, SH, SR 2 , OH, OR 2 , NO 2 , CN, CO, COOR 2 , NR 2 R 3 or NR 2 R 3 R 4+ X, where R 2 , R 3 and R 4 independently are H or a lower alkyl or lower alkoxy radical, and X − is a counter ion, with the proviso that R 1 is not equal to R 2 and R 1 is less bulky than R 2 , by reducing a corresponding ketone with a dehydrogenase having the polypeptide sequence of SEQ ID NO: 2 or having a polypeptide sequence having at least 95% sequence homology to the polypeptide sequence of SEQ ID NO: 2.