The strategic marriage of method and motif. Total synthesis of varitriol

Detailed in this report are several new efficient synthetic approaches toward the natural product anti cancer agent varitriol, culminating in a concise total synthesis. A common theme for these routes is that they employ a new catalytic stereoselective vinyl oxirane ring expansion reaction, which provides rapid access to the common cis-2,5-tetrahydrofuran core. The combination of careful synthetic design and proper selection of starting materials results in an excellent marriage between this new method (vinyl oxirane ring expansion) and the motif (varitriol).