Spectrometric identifications of sesquiterpene alcohols from niaouli (Melaleuca quinquenervia) essential oil

Oxidation and reduction reactions on alloaromadendrene and aromadendrene se squiterpene hydrocarbons have been investigated in order to produce alcohol s with an aromadendrene skeleton for checking the chemical structure and th erefore the identity of one main alcohol present in niaouli (Melaleuca quin quenervia) essential oil. Oxidation using m-chloroperbenzoic acid was carri ed out to produce two diastereoisomer epoxides and two corresponding aldehy de isomers for each sesquiterpene. Epoxide reductions yielded two alcohols ledol and viridiflorol, from alloaromadendrene and globulol and epiglobulol from aromadendrene. The structure determination of all compounds, i.e. epo xides, aldehydes, and alcohols, was achieved using spectrometric methods: 2 D-NMR and mass spectroscopy. The stereochemistry of known sesquiterpenic al cohols, viridiflorol and ledol, has been unambiguously established. (C) 200 1 Elsevier Science B.V. All rights reserved.