Total synthesis of the tricyclic skeleton of the natural Celastraceae sesquiterpenoids and related synthetic analogs

A concise and efficient synthesis of the C13 tricyclic core of the dihydro-β-agarofuran skeleton common to the natural Celastraceae sesquiterpenoids is described. The strategy entails a Mukaiyama aldol reaction of a tetrahydronaphthalene enol silane with acetone, epoxidation, ketone reduction, and acid-catalyzed cyclization. This key scaffold was converted into diverse polyhydroxylated derivatives, which were tested for insecticidal activity.