Synthesis of angiolam A.

The first total synthesis of angiolam A has been accomplished in 18 steps. Key steps include vinylogous Mukaiyama aldol reactions of aldehyde-derived dienol ethers, conjugate reduction of the resulting double bond followed by diastereoselective protonation and the Witzeman protocol for macrolactamization. Comparison of the optical rotation of the synthesized material with the isolation data established that the absolute configuration of angiolam A is opposite from the proposed structure.