Method for producing para-menthane-3,8-diol

Abstract

To offer a method of producing useful para-menthane-3,8-diol having the excellent repellent action to harmful living things, including noxious insects, in high purity and high yield, simply, and economically by the use of citronellal as a raw material compound. The above-mentioned problems are resolved by the production method of this invention wherein citronellal is treated with aqueous sulfuric acid solution of 0.02 to 1.0 wt. % in concentration to produce para-menthane-3,8-diol. In case of recovering the produced para-menthane-3,8-diol, a method is preferably adopted, wherein after the reaction product is extracted with an aliphatic hydrocarbon solvent of 5 to 8 in carbon number, the extract is cooled down at temperature higher than the melting point of said aliphatic hydrocarbon solvent and of -10.degree. C. or less to crystallize para-menthane-3,8-diol.

Dependencies are inferred from the claim text.