Syntheses and conformational analyses of mono- and trans-1,4-dialkoxy substituted cyclohexanes—the steric substituent/skeleton interactions
作者:Erich Kleinpeter、Jörg Thielemann
DOI:10.1016/j.tet.2007.06.094
日期:2007.9
trans-1,4-dialkoxy substituted cyclohexanes (alkyl=Me, Et, i-Pr, t-Bu) were prepared using the solvomercuration–demercuration (SM–DM) procedure. The axial⇋axial and axial,axial⇋equatorial, equatorial conformational equilibria of the products were studied by low temperature 1H and 13C NMR spectroscopy in CD2Cl2. The structures and relative energies of the participating conformers were calculated at both the
单-和反式-1,4-二烷氧基取代的环己烷(烷基= Me,Et,i- Pr,t- Bu)是使用溶剂化-脱汞(SM-DM)程序制备的。通过低温1 H和13 C NMR光谱法在CD 2 Cl 2中研究了产物的轴向,轴向和轴向,赤道,赤道构象平衡。在理论上的B3LYP(6-311G ∗ // 6-311 + G ∗)和MP2(6-311 + G ∗ // 6-311G ∗)水平上计算参与构象异构体的结构和相对能。在DFT的情况下,ΔG具有良好的相关性ø计算值与Δ ģ ö exptl获得。已针对构象分析的已建立模型讨论了构象异构体的结构和能量差异,即。空间和超共轭相互作用。另外,关于存在的超共轭,考虑了1 J H,C耦合常数。