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Readily available 1-aza-1,3-butadienes (enimines) react with methyl acetoacetate and acetylacetone in the presence of catalytic amounts of lithium iodide to form in high yields unsymmetrically substituted 1,4-dihydropyridines or cyclohexenones. The reaction pathway depends on the structure of the enimine used. This divergence was not observed when the enimines were reacted with dimethyl 1,3-acetonedicarboxylate to provide bicyclo[3.3.1]nonane-3-one derivatives in excellent yields in a remarkably stereoselective reaction.

The surface tensions of PbCl2-ZnCl2 binary melts have been measured by the maximum bubble pressure method in the temperature range up to 200•Ž above the liquidus. At each composition the surface tension shows a nearly linear decrement with rising temperature. From the values of surface tension and its temperature coefficient, the surface entropy and the surface enthalpy per unit area are determined for the binary melts. These quantities and the surface tension vary only slightly with increasing content of PbCl2 up to 50mol% PbCl2, but increase conspicuously in the PbCl2-rich side of the system as the content of. PbCl2 increases. The changes in liquid structure or the constituent ionic species have also been estimated on the basis of the results obtained in this experiment and the previously reported data on the density, electric conductivity and viscosity coefficient, etc.

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