Daniel D. Syrdal

Terpenes and sesquiterpenes of Chamaecyparis nootkatensis leaf oil.

Abstract The composition of the leaf oil of Chamaecyparis nootkatensis is reported. The terpene fraction consists of (−)-α-pinene, (+)-3-carene and (+)-limonene together with small amounts of (−)-β-pinene, myrcene and two unidentified hydrocarbons. The sesquiterpene fraction is largely a mixture of levoratory α-, β-, and γ-curcumenes with lesser amounts of (−)-α-copaene, (+)-α-ylangene, (+)-longifolene, (+)-δ-cadinene, (+)-γ-cadinene, (+)-β-bisabolene, β-farnesene, (+)-trans-nerolidol and three substances which have not been fully characterized. One of these appears to be a mixture of diastereomeric “calamenenes”; the others are new sesquiterpenes which we designate as α- and β-alaskene. Valencene and nootkatene, previously reported from the heartwood oil of this species, were not detected in the leaf oil. The biogenetic and chemotaxonomic implications of these results are discussed.

Widespread occurrence of two heteroannular dienes of the cadalane skeleton

Abstract Zonarene (II) and its epimer (I) have been identified as constituents in nine essential oils. Their structures and absolute configurations are established through chemical interrelationship with amorphenes and circular dichroism studies. Diene I occurs in both enantiomeric forms in nature.

Sesquiterpenes—identification of dehydrogenation products

Abstract Highly reproducible GLC retention data for common sesquiterpene dehydrogenation products are presented. The composition of the sesquiterpene portions of ginger oil, cade oil, celery seed oil, vetiver oil, technical guaiene, and the leaf oil of Chamaecyparis nootkatensis has been studied by small-scale dehydrogenation coupled with GLC analysis. The absence of eudalene from the mixture obtained from C. nootkatensis confirms our contention that the leaf oil contains (in contrast to the wood oil 3 ) no selinenes or nootkatenes 4 .