Total synthesis of (+)-nankakurines A and B and (plusmn)-5-epi-nankakurine A

The first total syntheses of the Lycopodium alkaloids (+)-nankakurine A, (+)-nankakurine B and the originally supported structure of nankakurine A is feature a demanding intramolecular azomethine imine cycloaddition as the key step is reported. The reaction generated the octahydro-3,5-ethanoquinoline moiety and installed the correct relative configuration at the spiropiperidine ring juncture.