SYNTHESIS AND CHARACTERIZATION OF SOME NEW FLAVONOIDS FROM 6,8-DIACETYL-5-HYDROXY-2,2-DIMETHYLCHROMAN

The condensation of 6, 8-diacetyl-5-hydroxy-2. 2-dimethylchroman with 2 molar proportions of various methoxy substituted aromatic aldehydes in the presence of alcoholic alkali furnishes a mixture of mono and di chalcones. Oxidation of these chalcones with SeO2 in amyl alcohol fail s to yield pure reaction products, but oxidation with dimethylsulphoxi de/iodine furnishes the corresponding flavones in about 70% yields. Th e new chalcones and the corresponding flavones have been characterized by their physical and spectral data. Attempts to isomerize the mono a nd dichalcones to the respective flavanones by refluxing in methanolic HCl or stirring with orthophosphoric acid at room temperature have be en unsuccessful.