One-pot three-component synthesis of tetrahydrobenzo[b]pyrans catalyzed by cost-effective ionic liquid in aqueous medium

A simple and efficient method is proposed for the synthesis of tetrahydrobenzo[b]pyrans with aromatic aldehydes, active methylene compounds, and dimedone using basic ionic liquid catalyst in water. The procedure offers several advantages including short reaction time, good yield, easy procedure, and good recyclability of catalysts, which may be a practical alternative to conventional processes for preparation of 4-hpyrans.