Synthesis and antibacterial activities of pyrano[3,2-b]pyranones from kojic acid, ethyl cyanoacetate, and benzaldehydes in aqueous K2CO3

Pyrano[3,2-b]pyranones are prepared in good yields from three-component coupling of kojic acid, ethyl cyanoacetate, and benzaldehydes in aqueous K2CO3. The synthetic compounds exert moderate activity against both Gram positive and Gram negative bacteria and their effectiveness is higher against Bacillus subtilis.