Department of Chemistry, University of California, Irvine, California 92697-2025, United States.
J Org Chem. 2011 Oct 7;76(19):7706-19. doi: 10.1021/jo200950s. Epub 2011 Sep 14.
The axial conformer of several 4-substituted cyclohexanone hydrazone salts was found to predominate in solution. Changes in the charge of the molecule and the polarity of the solvent led to changes in the conformational preference of each molecule that were consistent with electrostatic stabilization of the axial conformer. (1)H NMR spectroscopic analysis was utilized to determine the structure of cyclohexanone-derived substrates by comparison to conformationally restricted trans-decalone derivatives and computational models. X-ray crystallography demonstrated that the axial configuration of a pendant benzyloxy group is the preferred conformation of an iminium ion in the solid state. The structure of a neutral hydrazone was also determined to favor the axial configuration for a pendant benzyloxy group in the solid state.
研究发现，几种 4-取代环己酮腙盐的轴向构象在溶液中占主导地位。分子的电荷变化和溶剂的极性导致每个分子的构象偏好发生变化，这与轴向构象的静电稳定化一致。（1）H NMR 光谱分析用于通过与构象受限的反式-十氢萘酮衍生物和计算模型进行比较来确定环己酮衍生底物的结构。X 射线晶体学表明，在固态中，侧链苄氧基的轴向构型是亚胺离子的优势构象。中性腙的结构也表明，在固态中，侧链苄氧基的轴向构型是有利的。
