| 摘要 |
A method for producing (S)-cyanohydrins of general formula <IMAGE> (I) in which R and R' independently represent (1) hydrogen; (2) a substituted or unsubstituted saturated alkyl group which may include amine, imine, hydroxy, C1-C8-alkoxy, halogen, carboxyl, C3-C20-cycloalkyl groups and/or a N,O,S-heteroatom-substituted aromatic ring as substituent; (3) a substituted or unsubstituted, singly or multiply unsaturated alkenyl- or alkinyl group which may include one or several amine, imine, hydroxy, C1-C8-alkoxy, halogen, carboxyl, C3-C20-cycloalkyl groups and/or one optionally N,O,S-heteroatom-substituted aromatic ring as substituents; (4) a substituted or unsubstituted aromatic or heteroaromatic group. The method includes an enzyme-catalyzed conversion of carbonyl compounds of general formula II <IMAGE> (II) with hydrogen cyanide or a substance supplying hydrogen cyanide or CN- for the conversion in the presence of an amount of an immobilized (S)-oxynitrilase which catalyzes the conversion. The use of nitrocellulose as carrier for the immobilized (S)-oxynitrilase results in a distinct increase of the yield of (S)-cyanohydrin and of the enantiomeric excess compared to the traditional cellulose carrier material.
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