Synthesis of 2,3-Benzobicyclo[3.3.1]non-2-enes\nvia\na Cascade of Domino Carbocation Migration/Interrupted Ritter Reaction\nand Dienone-Phenol Rearrangement

The\n2,3-benzobicyclo[3.3.1]non-2-ene scaffold is a bridged\nbackbone\nof many bioactive natural products. The development of a concise tactic\ntoward this architecture is of keen interest and highly challenging.\nHerein, we disclose a novel cascade protocol for realizing this target.\nThis approach relies on a domino sequence of carbocation rearrangement\nand Ritter reaction of the taiwaniaquinoid scaffold derivatives. A\nprocess of dienone-phenol rearrangement was postulated to be involved.\nSeveral potentially useful compounds with this intricate bridged ring\nwere obtained in good overall yields (59–83%, over 2 steps).