Illustrated Glossary of Organic Chemistry

Menthol: IUPAC name (1R,2S,5R)-2-isopropyl-5-methylcyclohexanol. A terpenoid natural product produced by many plant species. Although the molecule has eight stereoisomers, the majority of natural sources produce (-)-menthol, the stereoisomer shown below. Menthol is notable for its characteristic, pleasant odor, (enhanced by its ease of sublimation and relatively high vapor pressure at room temperature) and mild analgesic properties, for which it is employed in numerous medicinal products.


Molecular structure of (-)-menthol
Crystals of (-)-menthol.