Cupressene and Other Diterpenes of Cupressus Species

Abstract

Cupressene, as originally isolated from Cupressus macrocarpa, is shown to be a 1 : 2 mixture of (+) isophyllocladene with (+)-isohibaene (13α-beyer-15-ene) rather than with (-)-hibaene (beyer-15-ene) as previously claimed. Corrections to the optical rotations of (+)-phyllocladinol and (-)-abieta-7,13-diene and g.l.c. data for diterpene hydrocarbons are reported. Analysis of the diterpene hydrocarbon composition of the foliage of 27 specimens from four Cupressus species reveals significantregularities.