Synthesis of the 11-membered ring of the marine alkaloids, madangamines

The first successful attempt at synthesizing the 11-membered ring of madangamine alkaloids is described. The synthesis involves intramolecular N,O-acetalization of a cyclohexanone derivative, cross-coupling reaction with (Z)-vinylstannane, and intramolecular reductive amination for elaboration of the 11-membered macrocycle.