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).     

Stereoselective total synthesis of (+)-varitriol

Stereoselective total synthesis of (+)-varitriol, an antitumor natural product, was accomplished by two versatile strategies starting from the commercially available d-(−)-ribose and ethyl (S)-lactate. The key steps involved in the synthesis of the target molecule are epoxidation, cyclization, dihydroxylation and Diels-Alder reaction.