Ali Shaikh A, Wazeer Mohamed I M
Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
Spectrochim Acta A Mol Biomol Spectrosc. 2008 Nov 1;71(1):292-5. doi: 10.1016/j.saa.2008.02.040. Epub 2008 Mar 8.
A series of beta-phenyl-2-isoxazolidineethanols having cis-disposed substituents at C(4) and C(5) has been prepared by asymmetric nitrone cycloaddition reactions and their NMR spectra recorded over a wide range of temperatures. The spectra in CDCl3 at low temperatures indicate the presence of two interconverting invertomers for some of the tri-substituted isoxazolidines. The effect of H-bonding--intramolecular in CDCl3 and intermolecular in CD3OD--on the population ratio of the nitrogen invertomers has been investigated. The nitrogen inversion barriers are determined using complete line-shape analysis, and their dependence on solvent is discussed.
通过不对称硝酮环加成反应制备了一系列在C(4)和C(5)处具有顺式取代基的β-苯基-2-异恶唑烷乙醇，并在很宽的温度范围内记录了它们的核磁共振光谱。低温下在CDCl3中的光谱表明，一些三取代异恶唑烷存在两种相互转化的对映体。研究了氢键（在CDCl3中为分子内氢键，在CD3OD中为分子间氢键）对氮对映体总体比例的影响。使用完整的线形分析确定了氮翻转能垒，并讨论了它们对溶剂的依赖性。
