( R)-Oxynitrilase-catalyzed synthesis of ( R)-2-trimethylsilyl-2-hydroxyl-ethylcyanide

Abstract

The enantioselective synthesis of ( R)-2-trimethylsilyl-2-hydroxyl-ethylcyanide with ( R)-oxynitrilase from defatted almond meal in a biphasic system was successfully performed. The influences of some factors on the reaction were investigated systematically. Diisopropyl ether was found to be the best for this reaction among all the organic solvents explored. The optimal aqueous phase content, concentrations of crude enzyme, acetyltrimethylsilane, acetone cyanohydrin, shake speed, buffer pH, reaction temperature were 13% (v/v), 5% (w/v), 0.02 M, 0.04 M, 150 rpm, 5.0, 40 °C, respectively, under which the initial reaction rate, substrate conversion and product e.e. were 5.87 mmol/l h, 99.5 and 99.0%.