Partial synthesis of ent-kaur-16-ene-15β,18-diol and ent-kaur-16-ene-7α,15β,18-triol

Abstract

Treatment of ent-15β,16β-epoxykauran-18-ol (V) with boron trifluoride–ether complex in dimethyl sulphoxide or direct photo-oxygenation of ent-kaur-15-en-18-ol (IV) gave the expected ent-kaur-16-ene-15β,18-diol (I). This product is suggested to be identical with natural candidiol. Treatment of ent-15β,16β-epoxykaurane-7α,18-diol (VIII)(natural sideroxol) with boron trifluoride–ether complex in dimethyl sulphoxide or photo-oxygenation of ent-kaur-15-ene-7α,18-diol (II)(natural sideridiol) gave ent-kaur-16-ene-7α,15β,18-triol (VII).