Facile Synthesis of m-Terphenyls by Ring Transformation of 2H-Pyran-2-ones

An alternative approach for the synthesis of meta-terphenyls 3a-g functionalized with electron-withdrawing or -donating groups is described and illustrated by carbanion-induced ring transformation of 6-aryl-2H-pyran-2-ones 1a-g with propiophenone 2 in excellent yields.