Enantioselective Formal Synthesis of (+)-Madangamine A

An enantioselective formal synthesis of the marine alkaloid madangamine A using phenylglycinol-derived lactam 1 as the starting enantiomeric scaffold is reported. The synthesis involves the construction of the C-9 substituted diazatricyclic ABC core and the final closure of D and E rings from the polyunsaturated skipped intermediate 19.