Abstract: The present invention relates to a process for the enantioselective enzymatic reduction of keto compounds, in particular of 4-halo-3-oxobutyric acid esters, to the corresponding R-alcohols or S-4-halo-3-hydroxybutyric acid esters, respectively, using an R-specific oxidoreductase in the presence of a cofactor.

Abstract: The invention relates to a process for the preparation of 2-butanol by enzymatic-catalyzed reduction of 2-butanone with a carbonyl reductase and a coenzyme and is characterized in that an aqueous phase, which contains the carbonyl reductase and the coenzyme, is contacted with an alcoholic phase, which is not miscible with the aqueous phase and contains 2-butanone, in order to reduce the 2-butanone, with the proviso that the alcohol present in the alcoholic phase is a secondary alcohol capable of regenerating the coenzyme and exhibiting a boiling point which lies above that of water, whereupon the 2-butanol formed is separated.

Abstract: The invention relates to a process for the preparation of 2-butanol by enzymatic-catalyzed reduction of 2-butanone with a carbonyl reductase and a coenzyme and is characterized in that an aqueous phase, which contains the carbonyl reductase and the coenzyme, is contacted with an alcoholic phase, which is not miscible with the aqueous phase and contains 2-butanone, in order to reduce the 2-butanone, with the proviso that the alcohol present in the alcoholic phase is a secondary alcohol capable of regenerating the coenzyme and exhibiting a boiling point which lies above that of water, whereupon the 2-butanol formed is separated.

Abstract: The invention relates to a NADH-dependent oxidoreductase obtained from yeasts, for example, of the genus Pichia, more particularly from Pichia capsulata. The oxidoreductace used in an enzymatic process for enantioselective reduction of organic ketocompounds to the corresponding (S)-hydroxy compounds and in an enzymnatic process for anantioselective preparation of (S)-hydroxy compounds in a two phase system using the isolated, recombinantly overexpressed oxidoreductacse from Pichia capsulata.