Synthesis and conformational studies of newly synthesized cis-2r,6c-distyryltetrahydro thiopyran-4-one and its oxime: comparison of experimental and theoretical NMR spectral data.

The cis-2r,6c-distyryltetrahydro thiopyran-4-one (4) was synthesized by the reaction of dicinnamylacetone with hydrogen sulphide. cis-2r,6c-distyryltetrahydro thiopyran-4-one oxime (5) was synthesized via oximination of 4. The synthesized compounds were characterized by IR, NMR spectral studies and elemental analysis. The proton and carbon chemical shift values were unambiguously assigned using two dimensional NMR (1H1H COSY, HSQC, HMBC, NOESY) spectra. 1H NMR and 13C NMR chemical shifts of 4 were also obtained by the density functional theory (DFT) using 6-311++G(d,p) basis sets and the theoretical values were compared with experimental values.