A convenient one-pot synthesis of pyrano[3,2-c]quinolin-2,5(6H)-dione and 2H,5H-pyrano[3,2-c]chromene-2,5-dione derivatives

The preparation of novel pyrano[3,2-c]quinolin-2,5(6H)-dione and 2H,5H-pyrano[3,2-c]chromene-2,5-dione derivatives starting from 4-hydroxyquinolin-2(1H)-ones and 4-hydroxy-2H-chromene-2-one with chlorocarbonyl ketenes is described. This method provides a new route to produce fused pyrano derivatives in good to excellent yields in a short experimental time.