| 摘要 |
Method for the preparation of an enantiomerically enriched ester, in which a mixture of the enantiomers of the corresponding secondary alcohol is subjected, in the presence of an acyl donor, to an enantioselective conversion in the presence of a racemisation catalyst upon which the ester is formed and an acyl donor residue is obtained, and in which the acyl donor residue is irreversibly removed from the phase in which the enantioselective conversion takes place. Preferably the enantioselective conversion is carried out enzymatically and a transfer hydrogenation catalyst is used as racemisation catalyst.The secondary alcohol can be formed in situ from the corresponding ketone, in the presence of a hydrogen donor. It is also possible to use a mixture of the secondary alcohol and the corresponding ketone as substrate.Preferably the acyl donor is chosen so that the acyl donor residue is converted in situ into another compound and/or the acyl donor residue is removed via distillation under reduced pressure.The enantiomerically enriched esters obtained can subsequently be converted into the corresponding enantiomerically enriched alcohols, which are desirable intermediate products in the preparation of liquid crystals, agro chemicals or pharmaceuticals.
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