The Question of Conformational Restriction in the trans-Cyclononene Ring of Caryophyllene

Abstract

The possibility that the barrier to rotation of the trans double bond within the nine-membered ring of caryophyllene might be high enough to prevent the interconversion of conformers 2 and 3 near room temperature has been examined. Contrary to earlier reports, it has been found that two trans epoxides are formed on peracid epoxidation of caryophyllene and hence both conformers are present. Attempts to determine whether 2 and 3 are interconverting near room temperature were inconclusive.