Radical Cation Salts Induced aza-Diels-Alder Reaction: Synthesis of Hexahydrofuro[3,2-c]- quinoline Derivatives

Aza-Diels-Alder reaction between imines and 2,3-dihydrofuran under radical cation induced conditions was achieved and series of hexahydrofuro[3,2-c]quinoline derivatives was prepared. The stereoselectivity was affected by the substituents on imines, which revealed a stepwise mechanism. A radical cation mediated mechanism was proposed to rationalize the formation of the products.