Theoretically p-menthenes, C10H18, may be regarded as derived from p-menthane (1) by extraction of two neighboring hydrogens. Of the six p-menthenes (2-7) this generated, (3) and (7) exist in cis- and trans- forms and optical isomerism is displayed by (2), (3), and (4). Outstanding substrates for mechanistic studies and chemical processings, these hydrocarbons are no less valuable and versatile than the much-trumpeted p-menthadienes.
Much literature has focused on p-menthenes since the publication of their chemistry by Windemuth. It is worthwhile to discuss the far-flung contributions in the area. To begin, we will scan the many facets of the fascinating chemistry of p-menth-3-ene (4), the doyen among the p-menthenes.