An efficient protocol for the synthesis of dihydropyrano [2,3-c] chromenes derivatives by one-pot threecomponent
reaction of aromatic aldehydes, malononitrile or methyl cyanoacetate, and 4-hydroxy coumarin has been
developed using catalytic amount (10%) of three different catalysts piperidine, triethyl amine, and natrium carbonate in
aqueous media. The present protocol has significant features such as easy set-up and work-up, environmentally benign,
high yields, short reaction times.