Diels–Alder/Oxidative Aromatization Approach towards the All‐Carbon DEF Tricyclic Skeleton of Daphenylline

Daphenylline is a recently isolated Daphniphyllum alkaloid with an unprecedented novel hexacyclic scaffold. In this study, the synthesis of the fused all-carbon DEF tricyclic skeleton of daphenylline has been accomplished. Key steps of the reported sequence involve Evans asymmetric allylation, aldol condensation, Diels-Alder reaction, and oxidative aromatization reactions. The developed strategy might lead to the total synthesis of daphenylline.