Synthesis of the 4-azatricyclo[5.2-2.04.8] undecan-10-one core of Daphniphyllum alkaloid calyciphylline A using a Pd-catalyzed enolate alkenylation

The ABC ring system of the natural product calyciphylline A has been synthesized. The key steps were a palladium-catalyzed intramolecular coupling of an amino-tethered vinyl bromide with a ketone using potassium phenoxide as the base to generate the C-ring and a hydroxyl-directed hydrogenation of an exocyclic double bond to give the azatricyclic ketone 1.