SYNTHESES OF SESQUITERPENE EPOXIDES AND ALCOHOLS FROM GAMMA-GURJUNENE

gamma-Gurjunene, a natural sesquiterpene isolated from gurjun balsam, is obtained by isomerization of alpha-gurjunene in acidic medium. Oxid ation of gamma-gurjunene by reaction with m-chloroperbenzoic acid yiel ded a mixture of two monoepoxides and two diepoxides. Reduction reacti on of a mixture of diepoxides with 4 equiv of lithium aluminum hydride or lithium triethylborohydride allowed isolation of a single diol in 93% yield. Four diols were obtained when reduction was realized with 2 equiv of reducing agent, including an epoxy alcohol, two enediols, an d a dienol. The structure formulas of the compounds were determinated using one- and two-dimensional NMR and gas chromatography-mass spectro metry.