| 摘要 |
<p>The invention relates to a method for producing optically active cyanohydrins and the corresponding α-hydroxycarboxylic acids, starting from an aldehyde, hydrogen cyanide and an optically active vanadyl-salen catalyst, whereby the reaction mixture is reacted at a temperature of between 0 and 60 °C. Between 0.8 and 10 equivalents of hydrogen cyanide and between 0.0001 and 0.05 equivalents of vanadyl-salen catalyst in relation to the aldehyde, (concentration of between 0.5 and 4 mol/litre solvent), are preferably used. After said reaction the optically active cyanohydrin or after an acid hydrolysis the corresponding optically active α-hydroxycarboxylic acid can be isolated with a surplus of enantiomers. The vanadium catalyst used in the invention contains a salen ligand, whereby the ratio salen ligand: vanadium (IV) in the catalyst ranges between 1.4:1 and 10:1.</p> |
