Acid catalyzed ring transformation of benzofurans to tri- and tetrasubstituted furans.
An unusual Brønsted acid catalyzed benzofuran ring opening and furan ring closure sequence for the formation of tri- and tetrasubstituted furans is presented. Benzofuranyl carbinols and 1,3-dicarbonyls in the presence of a catalytic amount of an acid generated functionalized, polysubstituted furans in good to excellent yields via an unusual benzofuran ring opening and furan recyclization process. This reaction is found to be general even on furyl carbinols; however, it generates the rearranged polysubstituted furans in moderate yields.
Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali , Sector 81, S A S Nagar, Manuali PO, Punjab 140 306, India.
Seema
S
Dhiman
S S V
SS
Ramasastry