First formal synthesis of (+)-nimbidiol. Synthesis, X-ray structure and anticancer activity of a novel ring C aromatic diterpene: dimethyl (+)-podocarpa-8,11,13-triene-12,13-dicarboxylate

A novel ring C aromatic diterpene (4) has been prepared in three steps from natural (+)-manool (1). The structure and anticancer activity data for 4 has been investigated. This key intermediate (4) was easily transformed into 7-deoxo nimbidiol dimethyl ether (8). The present work represents the first formal synthesis of (+)-nimbidiol (10).