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

The steam distillates of the family Myrtaceae are often found to contain th e three isomeric sesquiterpene alcohols, alpha-, beta- and gamma -eudesmol. Associated with these alcohols but not steam-distilled with them are two h ydrates of eudesmol, cryptomeridiol and 4-epicryptomeridiol, compounds whic h have not been previously reported in the Myrtaceae. These five alcohols a re the major by-products of the hydrolysis of hedycaryol, which can occur d uring leaf ageing or distillation. The use of (H2O)-O-18 during distillatio n implicated the presence of hedycaryol prior to distillation by trapping t he eudesmyl-carbocation formed during the hydrolysis. Copyright (C) 2000 Jo hn Wiley & Sons, Ltd.