A synthetic route to the alkaloids of the ervatamine group. First total synthesis of (±)-6-oxo-16-episilicine

A general route to silicine-methuenine alkaloids, exemplified by the synthesis of 6-oxo-16-episilicine, involving the nucleophilic addition of an acetylindole enolate to the pyridinium salt 2, methoxycarbonylation of the resulting 1,4-dihydropyridine, controlled catalytic hydrogenation, cyclization on the indole 3-position and further functional group manipulations, is reported.