New Efficient Synthesis of CombretastatinA-4 via Colvin Rearrangement

A new four-step approach for the synthesis of anticancer agentcombretastatin A-4 (CA-4) has been developed. The method includesthe Colvin rearrangement of the benzophenone derivative phenstatinto the key diarylalkyne followed by stereoselective semi-reductionto CA-4 in good overall yield.