Two oleanane triterpenoids from Gordonia ceylanica and their conversions to taraxarane triterpenoids

摘要

Chemical investigation of the hot hexane extract of the stem bark of Gordonia ceylanica afforded two new oleanane triterpenoids, 3 beta-acetoxy-11 alpha,13 beta-dihydroxyolean-12-one (1) and 3 beta,11 alpha-diacetoxy-13 beta-hydroxyolean-12-one (2). The attempted acid hydrolysis of these two compounds resulted the dehydration and subsequent methyl group migration to afford the taraxarane triterpenoids 3 beta,11 alpha-dihydroxytaraxer-14-en-12-one (4) and 3 beta-hydroxy-11 alpha-acetoxytaraxer-14-en-12-one (5), respectively. These taraxaranes have not been previously reported. (C) 2000 Elsevier Science Ltd. All rights reserved. [References: 9]