Facile synthesis of regio-isomeric naphthofurans and benzodifurans

Naphtho[1,2-b]furans , naphtho[2,1-b]furans , benzo[1,2-b:5,4-b′]difurans , benzo[1,2-b:4,5-b′]difurans , and benzo[1,2-b:4,3-b′]difurans were synthesized by base-catalyzed cyclization reaction of the corresponding o-alkoxybenzoylarene derivatives. The o-alkoxybenzoylarenes were obtained from the etherification reaction of the o-hydroxybenzoylarenes, which were prepared either by the reaction of methoxyarenes with benzoyl chloride in the presence of aluminum chloride or by photo-Fries rearrangement of aryl benzoates.