Stereoselective synthesis of oxa- and aza-angular triquinanes using tandem radical cyclization to vinylogous carbonates and carbamates

Tandem radical cyclization to vinylogous carbonates and carbamates is developed for a new, highly stereoselective synthesis of heterocyclic angular triquinanes. The strategy is also useful to gain access to oxa- and azatriquinanes, which incorporate the spiroindoline moiety. The method is further extended to the synthesis of lactone-bearing as well as uracil-fused angular triquinanes. © 2012 American Chemical Society.