A novel ethylenediammonium diformate–polyethylene glycol (EDDF-PEG₆₀₀) system was developed as a catalyst for the Knoevenagel condensation and Knoevenagel initiated three-component one-pot synthesis of 4H-pyrans at room temperature with high yields and in short reaction times. Further, the EDDF-PEG₆₀₀ catalytic system was recycled six times without any appreciable loss in its activity and hence can be termed as a green, environmentally benign catalytic system. A plausible mechanism depicting the ambiphilic nature of EDDF (catalyst) and PEG (promoting medium) acting in synergy has been proposed.