Regioselective Synthesis of Functionally Crowded Benzenes at Room Temperature through Ring Transformation of 2H-Pyran-2-ones

An expeditious synthesis of highly substituted benzenes with electron withdrawing or donating substituents is described and illustrated by carbanion-induced ring transformation of 2H-pyran-2-one with malononitrile in excellent yield. The novelty of the reaction lies in the creation of an aromatic ring at room temperature from six membered-lactones under mild reaction conditions.