Ultrasound-assisted one pot synthesis of polysubstituted meta-terphenyls using ring transformation strategy

An ultrasound-assisted rapid synthesis of meta-terphenyls 9 by the carbanion-induced ring transformation reaction of 6-aryl-5-methyl-2H-pyran-2-ones 7 with functionalized ketones 8 under basic conditions at room temperature has been delineated. The present method gives an easy access to functionally crowded m-terphenyls 9 with notable features including mild reaction condition, remarkable functional groups tolerance, shorter reaction time and high product yields.