A New Class of Tricyclic Diterpenes from Eremophila georgei (Myoporaceae)

Abstract

The first example of a new class of tricyclic diterpenes together with two new viscidanes have been isolated from a variety ofEremophila georgei. The structures of the viscidane compounds were assigned on the basis of spectroscopic data and comparison with model compounds. The structure and relative stereochemistry of the lactone (2), which represents a new diterpene skeleton, were established by spectroscopic and X-ray crystallographic methods. The derivation of (2) from a viscidane is suggested.