ENANTIOMERIC COMPOSITION OF THE CHIRAL CONSTITUENTS OF ESSENTIAL OILS.2. SESQUITERPENE HYDROCARBONS

A number of sesquiterpene hydrocarbons commonly occurring in essential oils has been prepared as racemic mixtures by chemical synthesis. Pre parative gas chromatography with selectively per-O-alkylated cyclodext rins has been employed for the isolation of enantiomeric mixtures or p ure enantiomers from the essential oils of higher plants and liverwort s (Hepaticae). The enantiomers of alpha-curcumene, alpha- and beta-bis abolene, beta-elemene, delta-elemene, alpha-copaene, delta-cadinene, c is- and trans-calamenene, and bicyclogermacrene could be resolved by e nantioselective gas chromatography on capillary columns coated with cy clodextrin derivatives. The enantiomeric composition of these sesquite rpene hydrocarbons in various essential oils was determined.