Triterpenoids of Aglaia odorata. Configuration of trisubstituted epoxides

Abstract

Structures are established for three dammarane triterpenoids [(1c), (3a), and (3c)] isolated from Aglaia odorata. The stereochemistry at C-24 of these compounds and of aglaiol (1a) has been elucidated. The possibility that (3c)(a 24,25-dihydroxy-3-ketone) is identical with aglaiondiol, previously described as 3β,25-dihydroxy-5α-dammar-20-en-24-one, is discussed. It is shown that the configuration of trisubstituted epoxides can be conveniently determined by acid-catalysed methanolysis and application of Horeau's method to the resulting methoxy-alcohol.