Abstract:
Chalcones are one of the important classes of natural products with widespread distribution in fruits, vegetables, spices, tea and soya based foodstuff. It is a generic term given to compounds during the course of flavonoids biosynthesis in plants. Chalcones considered as the precurses of flavone, flavanones, isoflavonoids, aurones, catechins, anthocyanidines, and are abundant in edible plants. Chemically chalcones are open chain flavonoids in which two aromatic ring are by a three carbon a,13 unsaturated carbonyl system.
a,I3 unsaturated carbonyl moiety is a key constituent of many biologically important natural compound (flavanone). Among the derivatives of chalcones, 2'- hydroxychalcone are important building blocks for the synthesis of several natural products. Consequently, cyclization of 2'-hydroxychalcone has attracted tremendous attention for simplification or improvement of the exiting methods. Synthesis of flavanones from the cyclization of different 2'-hydroxychalcone derivatives with L-proline as a novel catalyst is described. This method proved to be an efficient with respect of several other methods reported under different reaction condition to affored the same products. All the products are characterized based on IHNMR, "CNMR, IR and GC MS spectral analysis.
