Selective production of cis- and trans-verbenol from (-)-and (+)-alpha by a bark beetle.

A unique biological system whereby optical isomers are selectively transformed to geometrical isomers is demonstrated in Ips paraconfusus. Exposure of adult male and female beetles to vapor of (-)-alpha-pinene resulted in the production of (+)-cis-verbenol, a pheromone of this species, whereas (+)-alpha-pinene was oxidized to (+)-trans-verbenol. It appears, therefore, that the ability of a bark beetle to produce its aggregation pheromone can be governed by the chirality of a precursor in the host tree.