Bicyclomangostin: a New Acid-Catalysed Cyclization Product from Mangostin

Abstract

Cyclization of mangostin with p-toluenesulfonic acid gave 1-isomangostin, 3-isomangostin, and a new cyclization product, bicyclomangostin (4). The structure of bicyclomangostin was determined by spectroscopic and X-ray crystallographic studies. The methyl ether derivatives (8) and (9) or (10) were produced on methylation of bicyclomangostin, depending on the method used.