A Concise Synthesis of Fumagillol.

A 13-step synthesis of (±)-fumagillol (1), the direct precursor of the potent angiogenesis inhibitors TNP-470 and fumagillin, from crotonaldehyde, diethylamine, and acrolein (see the scheme) has been achieved. The synthesis features a remarkable hetero-Claisen rearrangement. Small-molecule inhibitors of angiogenesis are promising chemotherapeutic agents for the treatment of cancer and inflammatory diseases.