V. Kuznetsov, A. E. Kuramshina, S. A. Bochkor
Sep 27, 2009
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Influential Citations
3
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Journal
Russian Journal of Organic Chemistry
Abstract
The interest to the structural investigation of 1,3-dioxanes, six-membered heteroanalogs of cyclohexane, originates from the features of their structure (the presence of two heteroatoms separated by sp3-carbon atoms), from their valuable pharmacological properties, and also from the application to the fine organic synthesis [1–5]. In the last decade computer simulations play an important role in conformationsl studies of such compounds. It was shown in particular that the conformational isomerization of unsubstituted 1,3-dioxane and also of 2,2-, 4,4-, and 5,5-dimethyl-1,3-dioxanes occurred between two degenerate in energy invertomers of chair (C and C*), and of 2-methyl-1,3-dioxane, between the conformers of equatorial and axial chair (Ce and Ca) along two materially equivalent paths [6–9]. This study is dedicated to the computer simulation of the paths of conformational isomerization of 4-trifluoromethyl-1,3-dioxane (I) by nonempirical quantum-chemical approximations RHF//STO-3G and 6-31G(d,p) in the framework of software HyperChem [10] under the conditions simulating the behavior of the molecules of this substance in the gas phase. It follows from the data of 1H NMR spectra of individual stereoisomers of 4-trifluoromethyl-5-methyl1,3-dioxane that the molecules of 1,3-dioxane I exist at room temperature prevailingly in the conformation of equatorial chair (Ce) [11].