Iodine catalyzed synthesis of the chromene derivatives in one-pot

Iodine catalyzed one-pot reactions of salicylaldehyde and dimolecular 1H-indene-1,3(2H)-dione, barbituric acids, 4-hydroxycoumarin, or 4-hydroxy-6-methylpyran-2-one were performed and provided a rapid, convenient and general approach to synthesize the chromene derivatives. 2-(11-Oxo-10,11-dihydroindeno[1,2-b]chromen-10-yl)-1H-indene-1,3(2H)-diones P1–P4 and 10-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-3-methylpyrano[4,3-b]chromen-1(10H)-ones P8–P9 were unprecedentedly prepared and structurally identified by NMR and Mass. The confirmation of structure by single crystal X-ray crystallography is reported for P3.