Synthesis of 4H-cyclopenta[c]furan-5(6H)-one derivatives

Abstract

In Ph3PAuCl/AgOTf/TsOH system, 2-diazo-5-alkynyl-1,7-diketo carbonyl compounds were transformed into diazo furans. Rh2(OAc)4-mediated conversion of the diazo furan derivatives into 4H-cyclopenta[c]furan-5(6H)-one derivatives was accomplished via C(sp2)−H insertion reaction at 4-position on the furan ring.