Approach to the Core Structure of the Polycyclic Alkaloid Palhinine A

A synthesis of the tricyclic partly substituted core structure of palhinine A was achieved. To reach the bicyclo[2.2.2]octane motif a domino Michael reaction was employed as a key step. After Arndt-Eistert homologation and intramolecular aldol reaction the isotwistane core could be obtained after simple functional-group manipulations.