Hydrolysis of hedycaryol : the origin of the eudesmols in the Myrtaceae

The steam distillates of the family Myrtaceae are often found to contain the three isomeric sesquiterpene alcohols, α-, β- and ƴ-eudesmol. Associated with these alcohols but not steam-distilled with them are two hydrates of eudesmol, cryptomeridiol and 4-epicryptomeridiol, compounds which have not been previously reported in the Myrtaceae. These five alcohols are the major by-products of the hydrolysis of hedycaryol, which can occur during leaf ageing or distillation. The use of H₂ ¹⁸O during distillation implicated the presence of hedycaryol prior to distillation by trapping the eudesmyl-carbocation formed during the hydrolysis.