(-)-Isopulegol and (+)-neo-isopulegol were isolated by a partial esterification of isopulegol mixture, obtained by the hydrolysis of the condensation product of (+)-citronellal with acetic anhydride. From the infrared spectra and optical rotation, it has been shown that isopulegol synthesized from (+)-citronellal mainly consists of (-)-isopulegol and (+)-neo-isopulegol in approximately equal amounts, but the presence of other isomers is negligible.
