Patchoulane sesquiterpenes

The sesquiterpenes important in odour terms mostly have complex cyclic structures. The problem of elimination of alcohols to produce olefins on attempted isolation is even more acute with sesquiterpenes than with monoterpenes because of their higher boiling points, which require more vigorous distillation conditions. The sesquiterpenes responsible for the odours of vetiver and patchouli oils have complex structures (21-24), which can only be reached by lengthy and hence uneconomic syntheses. As their names suggest, the vetivones occur in vetiver oil and the patchoulane derivatives in patchouli. 

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