Sodium benzenesulfinates, as a new organo catalyst, can be used to synthesize tetrahydro-
4H-chromene derivatives by three component reaction of cyclic β-dicarbonyl compounds, malononitrile,
and aromatic aldehydes, in H2O/EtOH, under ultrasound irradiation at room temperature. Inexpensiveness,
stability and the potential of being easily obtained can be noted as preponderance of
these catalysts. Furthermore, high conversions, short reaction times and cleaner reaction profiles are
some of the advantages of this method. Moreover, H2O/EtOH (7:3) was selected as a green solvent.