New Alkaloids of the ent-Kaurene Type From Anopterus Species (Escalloniaceae). I. The Structure and Reactions of Anopterine

Abstract

Anopterine (1), a major alkaloid from leaf and bark of Anoptevus macleayanus F. Muell. and bark of Anoptevus glandulosus Labill., has an unusual ent-kaurenoid skeleton with a C20-C14 linkage. Hydrolysis of anopterine gives anopteryl alcohol (5), C₂₁H₃₁N0₅, and two equivalents of tiglic acid. The chemical reactions of anopterine and anopteryl alcohol have been studied in detail, and a number of acetylation products and oxidation products have been obtained. Oxidation of anopteryl alcohol with potassium ferricyanide has given an unusual product (14) which has a C20,C12-oxide bridge and a C5,C6-epoxide group.