(R)-keto:cyanohydrin prepn. - by reacting ketone with prussic acid in organic solvent in presence of (R)-oxy:nitrilase; used in prepn. of alpha-hydroxy-alpha-(m)ethyl carboxylic acid

摘要

Prepn. of (R)-ketocyanhydrin (I) comprises reacting a ketone of formula R1COR2 with prussic acid in an organic solvent in the presence of (R)-oxynitrilase (EC4.1.2.10). In formulae, R1 = 2-5C, opt. halo-substd. alkyl or 3-5C alkenyl; R2 = CH3 or CH2CH3. Pref. the enzyme is immobilised and the solvent is diisopropyl ether. USE/ADVANTAGE - (I) is used to prepare alpha-hydroxy-alpha-(m)ethyl carboxylic acids (II) by acid-catalysed hydrolysis (claimed). (II) are intermediates for optically active cpds., e.g. insect pheromones, prostaglandin analogues and alpha-tocopherols. (I) is obtd. in high optical purity.