Patent ID: 6781012
Filing Date: 2004-08-24
Classification: C07C

Abstract:
A process for the preparation of chemically and optically highly pure (R)- and (S)-&agr;-hydroxycarboxylic acids, which comprises treating the hydrolysis solution obtained by acidic hydrolysis of the(R)- and (S)-cyanohydrins, prepared by enzyme-catalyzed addition of a cyanide group donor to the corresponding aldehydes or ketones, directly with an aromatic hydrocarbon, optionally in combination with a cosolvent selected from the group consisting of ethers and ketones, then extracting the mixture at hydrolysis temperature, whereupon after cooling of the organic phase the corresponding chemically and optically highly pure (R)- and (S)-&agr;-hydroxycarboxylic acids having an optical purity of over 98%ee crystallize out.