Stereoselective Synthesis of the Antileukemic Sesquiterpene (+)-Caparratriene from L-menthol and Tiglic Aldehyde

Abstract

A stereoselective synthesis of natural (+)-caparratriene was developed starting from commercially available L-menthol and tiglic aldehyde. The key step was a Wittig reaction of the latter with the triphenylphosphorane generated from (R)-(–)-citronellyl bromide. (+)-Caparratriene as a mixture (4:1) of 2E,4E- and 2E,4Z-stereoisomers is a known anticancer agent.