method for obtaining optically pure d, and the isomeres menthol, neomenthol and isomenthol

摘要

1369714 Menthol, neomenthol and isomenthol HAARMANN & REIMER GmbH 25 Feb 1972 [27 Feb 1971 2 Feb 1972] 8857/72 Heading C2C A process for the separation of the d- and lisomers of menthol, neomenthol or isomenthol comprises esterifying d,l-menthol, neomenthol or isomenthol with benzoic acid, a substituted benzoic acid or hexahydrobenzoic acid, selectively crystallizing the d,l-ester mixture obtained by inoculation of an oversaturated solution or a melt thereof with crystals of the pure d- or l-ester, and hydrolysing the recovered crystals.