Efficient one-pot synthesis of benzopyranobenzopyrans and naphthopyranobenzopyrans by domino aldol-type reaction/hetero Diels-Alder reaction of resorcinols and naphthols

The efficient one-pot synthetic approaches for benzopyranobenzopyrans and naphthopyranobenzopyrans are described. The key strategies involve ethylenediamine diacetate-catalyzed cyclization by domino aldol-type reaction/hetero Diels-Alder reaction of resorcinols and naphthols to benzaldehydes with O-allyl ether groups. These reactions provide a rapid route for the synthesis of novel types of poly-heterocycles with stereochemically defined quaternary carbon centers. (C) 2008 Elsevier Ltd. All rights reserved.