A stereoselective total synthesis of (±)-pseudoclovene-B

A stereocontrolled approach to the construction of the tricyclo[6.3.1.0(1,6)]dodecane ring system related to the sesquiterpene pseudoclovene-B (3) is delineated. Starting from the indanone 4, the bromophenol 5 was prepared in a straightforward manner. An aryl participated intramolecular cyclisation of 5 afforded the tricyclic dienone 6 which was stereoselectively converted into the A/B cis-fused ketone 7 through the intermediates 13 and 14 or through the intermediate 15. The tosylhydrazone derivative of 7 was treated with methyl lithium to furnish (+/-)-pseudoclovene-B in high yield. (C) 2002 Elsevier Science Ltd. All rights reserved.