Synthesis and structure of 3-oxopyrano[3,4-c]pyridines

Acylation of the enamine of 2,2-dimethyltetrahydropyran-4-one with acid chlorides produced -acylpyran-4-ones which give 3-oxopyrano[3,4-c]pyridines when treated with cyanoacetamide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1137–1142, August, 1989.     

σ,π-Conjugation in organomercurial systems

Two series of compounds LHgL′ are described. In series I, L = L′ = organic radical with an oxo group in position 2 or L′ = Cl, in series II, L = L′ = allylic radical or L′ = Cl. Some compounds possess chemical properties of conjugated systems (IA, IIA), while others do not possess such properties (IB, IIB). The J¹³C¹⁹⁹Hg) coupling constants and chemical shifts in ¹³C NMR spectra, the integral intensities of multiple bond vibrations in Raman spectra, the half-wave reduction potentials and the resonance energies in mass spectra of the negative ions are compared. The main contribution to the observed differences between compounds A and B is made by interaction of the CHg σ-bond with the π-system (σ, π-conjugation).