A highly stereoselective route to medium-ring-sized trans-alkenolides via oxidative fragmentation of bicyclic oxycyclopropane precursors: application to the synthesis of (+)-recifeiolide

A new approach to the synthesis of medium-ring-sized trans-alkenolides, based on the oxidative fragmentation of a three-carbon ring in hydroxyalkyl substituted bicyclo[n.1.0]alkan-1-ols readily available from 2-alkylidenecycloalkanones, is described. This methodology was applied to the six-step transformation of cyclooctanone to the natural 12-membered trans-alkenolide antibiotic (+)-recifeiolide.