Asymmetric Total Synthesis of (−)-Lemnalemnane C

The first asymmetric total synthesis of tricyclic sesquiterpenoid lemnalemnane C, which exhibits strong in vivo angiogenesis-promoting activity, has been accomplished. The key synthesis steps include the construction of two five-membered rings via pinacol coupling and the stereoselective introduction of an allyl group with double-bond isomerization.