Dimedone was condensed with arylaldehydes in 1:1 ratio to give 2-(benzylidene)—5,5-dimethylcyclohexane-1,3- diones in excellent yields in the presence of a number of catalysts in aqueous medium. The catalysts included lithium chloride, sodium acetate, magnesium sulfate, barium chloride, zinc acetate, sodium chloride, alanine, sodium sulfate, (sodium sulfate+alanine). Malononitrile was condensed with arylaldehydes in 1:1 ratio to give 2- (benzylidene)-malononitriles to give high yields in the presence of TBAB and sodium sulfate.
