ISOALANGIDIOL MONOACETATE, A TRITERPENE ALCOHOL

Isoalangidiol (3 alpha, 18 alpha-B':A'-neogammacerane-3,18-diol) has b een extracted as a natural product from the leaves of Alangium lamarck ii Thw. (Alangiaceae). The crystal structure study of its monoacetate, C32H54O3, was undertaken in order to ascertain the conformation of th e compound. The four six-membered rings are in chair conformations. Th e five-membered ring is distorted from a plane and is twisted, with a C19-C18-C17-C21 torsion angle of -43.0(4)degrees. The molecular parame ters of the compound are all within normal limits.