In the presence of a catalytic amount of NEt₃, ethyl 4,4,4-trifluoro-3-oxobutanoate 1 reacted readily with arylidenemalononitriles 2 in ethanol at room temperature. It gave two products 2-trifluoromethyl-3,4-dihydro-2H-pyran derivatives 3 and 2-(trifluoromethyl)piperidine derivatives 4, the ratio of 3 and 4 was depended on the substrates 2 and reaction solvents. Reflux of the ethanol solution of 4 with a catalytic amount of NEt₃ afforded 2-trifluoromethyl-1,4,5,6-tetrahydropyridine derivatives 5 in moderate to good yields. The structures of new compounds 3, 4 and 5 were determined by spectral methods, microanalysis and X-ray diffraction analysis. A possible reaction mechanism for the formation of 3, 4 and 5 was presented.

中文翻译：

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4,4,4-三氟-3-氧代丁酸乙酯与芳基丙二腈反应的研究

在催化量的NEt ₃的存在下，4,4,4-三氟-3-氧代丁酸乙酯1在室温下容易与芳基丙二腈2在乙醇中反应。它得到两个产物2-三氟甲基-3,4-二氢-2 H ^ -吡喃衍生物3和2-（三氟甲基）哌啶衍生物4，比例3和4是依靠衬底2和反应溶剂。用催化量的NEt ₃回流4的乙醇溶液，得到2-三氟甲基-1,4,5,6-四氢吡啶衍生物5中等至良好的产量。新化合物的结构3，4和5分别通过光谱法，元素分析和X射线衍射分析来确定。为形成一种可能的反应机理3，4和5提出。