Facile synthesis of regio-isomeric naphthofurans and benzodifurans

Abstract

Naphtho[1,2- b]furans 1a– f , naphtho[2,1- b]furans 2a– f , benzo[1,2- b:5,4- b′]difurans 3a– b , benzo[1,2- b:4,5- b′]difurans 4a– b , and benzo[1,2- b:4,3- b′]difurans 5a– b 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.