Four stereoisomers of verbenol are known. For the cis isomer, the two methyl groups (-CH3) are on the same side of the carbon ring as the hydroxy group (-OH), and for the trans isomer, they are on the opposite sides. Again, there are enantiomers of each form that exhibit optical activity, that is, turn the plane of linearly polarized light as it passes through the substance or its solution.
trans-Verbenol is a mountain pine beetle pheromone that attracts insects to a tree.[1]cis-Verbenol is an aggregation pheromone of Ipstypographus[2] and Dendroctonus ponderosae Hopkins.[3]
Typically, verbenol and related cyclic monoterpenes are available as non‐racemic mixtures of their enantiomers.[4] There are methods to increase enantiomeric excess (optical purity) of verbenol and to isolate individual enantiomers.[5][6]
^Mori, Kenji et al. Synthesis of Optically Pure (1S, 4S, 5S)-2-Pinen-4-ol (cis-Verbenol) and Its Antipode, the Pheromone of Ips Bark Beetles. https://doi.org/10.1080/00021369.1976.10862248
