METHOD FOR ISOLATING (-)-MENTHOL STEREOISOMER Russian patent published in 2006 - IPC C07C35/12 C12P41/00 

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for isolating (-)-menthol stereoisomer from a racemic mixture comprising eight stereoisomers of compound of the formula (III): wherein R₁ means isopropyl group. Method involves the following steps: (1) contacting the racemic mixture in an organic solvent with an esterifying agent and enzyme that esterifies stereospecifically OH-group of (-)-menthol for time sufficient for conversion of the necessary percent part of (-)-menthol to compound of the formula (IV) being without preparing other stereoisomers by the esterification reaction and wherein R₁ has values given above; R₄ means alkyl or aryl group to yield the first reaction substance comprising compound of the formula (IV), organic solvent, stereoisomers of compound of the formula (III) not subjected for this conversion and by-side reaction products; (2) distillation of the first reaction product with isolation of compound of the formula (IV)), and (3) hydrolysis of compound of the formula (IV) to yield the end compound of the formula (III). Method provides isolating the single end stereoisomer of (-)-menthol from racemic mixture containing eight stereoisomers.

EFFECT: improve isolating method.

17 cl, 7 ex