Synthesis and spectral studies of pyranone derivative and its Cu(II), Co(II), Ni(II) and Zn(II) complexes

Under the thermolysis condition, 5-phenyl-2,3-dihydro-2,3-furandione (IV) in inert aprotic solvents as p-xylene at 130-140 degrees C yields 3-benzoyl-4-hydroxy-6-plienyl-2H-pyran-2-one (VI) via phenyl ketene (V). The compound (VI) was converted into the corresponding 3-benzoyl-4-hydroxy-6-plienylpyridin-2(1H)one (VII), and 3-benzoyl-2-oxo-6-phenyl-2H-pyran-4-yl acetate (VIII), by its reactions with ammonium hydroxydc, and acetic anhydride, respectively. On the other hand, a series of new various metal complexes (IX-XIa, XIb) of VI was synthesizec.. The results suggest that the compound VI as bidentate ligand indicate a binuclear structure for the Cu(II) complex with square-planar geometry. The Ni(II) and Zn(II) complexes are of tetrahedral and the Co(II) complex. is also octahedral geometry with water molecules at the axial positions. The structures of compounds and complexes were characterized on the basis of elemental analysis, Mass, IR, (1)H, and (13)C NMR spectra.