Correlation of diterpenes of the (–)-kaurane series and atractyligenin

Abstract

19-Nor-16α- and 19-nor-16β-(-)-kaurane (11) and (111) have been prepared by unambiguous methods from 16α-( -)-kaurane-3α,l7,19-triol (IV) and (-)-kaur-16-ene-3α,l9-diol (V) and have been identified with samples derived from atractyligenin, thus providing conclusive proof for the skeleton of the latter.