Triterpenoid compounds. II. Some dehydrations of 3β-hydroxytriterpenoids

Abstract

Dehydrations of methyl 3β-hydroxylupan-28-oate (methyl dihydrobetulate) and methyl 3β-hydroxyurs-12-en-28-oate (methyl ursolate) have been carried out by several different procedures and the constitutions of the crystalline products established. The reactions of β-amyrin methanesulphonate have been re-examined but no product corresponding to α-amyradiene-IV (Noller and Hearst 1950) was obtained crystalline. Reduction of methyl ursolate methanesulphonate with lithium aluminium hydride afforded uvaol.