The Chemistry of <i>Eremophila</i> spp. XXII. New Eremane Diterpenes from <i>E. fraseri</i>

Abstract

The resin components of different collections of the highly variable Eremophila fraseri F. Muell. Have been examined. Five new eremane diterpene acids have been characterized and evidence for their structures is presented. The structure of a new diterpene, also isolated from E. fraseri, has been determined by X-ray crystallographic methods. The carbon skeleton of this new diterpene incorporates a tricyclo[6.2.1.01,5]undecane ring system.