METHOD FOR PRODUCING OPTICALLY ACTIVE, RACEMIC MENTHOL

摘要

PROBLEM TO BE SOLVED: To provide a method enabling to manufacture optically active menthol, desirably L-menthol and racemic menthol in a variety of quantity according to the demand without changing an enantioselective catalyst system and/or without excessively obtaining one of products for need of changing a reaction condition.SOLUTION: A method for producing menthol includes a process (a. 1) of obtaining a citronellal by catalyst-hydrogenation of a neral and/or a geranial, a process (b. 1) of obtaining an isopulegol by cyclizing citronellal in the presence of an acid catalyst, a process (c. 1) of purifying the isopulegol by crystallization, and a process (d. 1) of producing menthol by catalyst-hydrogenation of the isopulegol.