Photo-reversible Dearomative 6π-Desymmetrization

Synthesis of fused polycyclic complex natural products faces substantial challenges yet holds great promise for advancing drug discovery. Herein, we report a photo-reversible dearomative desymmetrization strategy that enables efficient access to construct tricyclic frameworks. Using alkenyl phenol precursors as starting materials, 310 nm UV light initiates a stereoselective 6π desymmetrization reaction and 450 nm visible light can reverse this transformation. The methodology's practical utility is validated by scalable construction of the norzoanthamine alkaloid core, enabling the divergent total syntheses of 15-hydroxynorzoanthamine, norzoanthamide B, and norzoanthaminone. 1. Introduction 2. The Dearomative 6Π-Desymmetrization 3. The Retro-dearomative 6π-Desymmetrization 4.