No abstract

No abstract

"C NMR spectra have been recorded for eleven piperidin-4-one oximes and for seven of them 'H NMR spectra have been recorded at 270 MHz. The effect of oxhation on the N M R chemical shitts is discussed.The conformations of the oximes are also discussed, based on the observed chemical shifts. Although several oximes appear to adopt a chair conformation, in the same manner as the corresponding ketones, the oximes of 3,5-dimethyl-2,6-diarylpiperidin-4-ones with cis-methyl groups seem to adopt an asymmetric non-chair conformation. Analysis of the chemical shifts of cis-2,6-dimethylcycloltexanone oxime suggests that this compound also exists in a non-chair conformation, and not in a chair conformation with two axial methyl groups as suggested previously.

No abstract

The structure of the title compound, C(17)H(16)OS, is primarily stabilized by T-shaped and parallel-displaced aromatic clusters. The distances between the centroids of the aromatic pairs are in the range 4.34-5.30 A. In the crystal packing, the molecules dimerize by means of pi-pi interactions of both face-to-face and edge-to-face types, and the aromatic rings associate in a cyclic edge-to-face tetrameric arrangement of the herring-bone type. These herring-bone interactions appear to insulate hydrogen-bond interactions in the crystal structure.

Six t(3)-aryl-r(2),c(4)-bisethoxycarbonyl-t(5)-hydroxy-c(5)-methylcyclohexanones (6-11) were synthesized by condensing ArCHO (Ar = Ph, p-O(2)NC(6)H(4), p-CH(3)OC(6)H(4), p-ClC(6)H(4), m-O(2)NC(6)H(4) and m-C(6)H(5)O(6)H(4)) with ethyl acetoacetate in the presence of methylamine and their (1)H and (13)C NMR spectra were recorded. (1)H-(1)H COSY and NOESY spectra were recorded for 6 and 7 and also HSQC and HMBC spectra for 6 and 8. Elemental analysis was carried out for all compounds. The mass spectrum was recorded for 8. All analytical data are consistent with the proposed molecular formulae. Analysis of NMR spectral data suggests that these compounds largely adopt chair conformations with the hydroxyl group occupying an axial orientation and all the other substituents occupying equatorial orientations. Long-range coupling (2-3 Hz) between the OH proton and the axial methylene proton at C-6 is observed in 6, 7, 8 and 11.

No abstract

No abstract