From a Theoretical Concept to Biochemical Reactions: Strain-Induced Bond Localization (SIBL) in Oxidation of Vitamin E
作者:Thomas Rosenau、Gerald Ebner、Amnon Stanger、Sharon Perl、Limor Nuri
DOI:10.1002/chem.200400265
日期:2005.1
from five- to six- and seven-membered rings, as predicted by the Mills-Nixon effect. The relative amounts of the products were determined at four different temperatures, and assuming that the product ratio represents the relative rates ratio, the relative enthalpy of activations could be obtained. Theoretically (at B3LYP/6-31G* theoretical level) four different intermediates were considered. Each of these
α-生育酚(维生素E的主要成分)氧化为邻醌甲基化物(oQM)的区域选择性在文献中主要通过定义不明确的术语“米尔斯-尼克森效应”进行了解释。在本文中,我们描述了11种α-生育酚衍生物的制备方法,它们的相变角之和互不相同,但保持电子因子不变。这些化合物经历了Ag(2)O氧化,形成两个异构的oQM,它们被乙烯基甲基醚捕获。已经发现,异构体产物比率随环角的变化而平滑地变化,而不是如由米尔斯-尼克森效应所预测的那样,在从五元环到六元环和七元环的情况下,一个区域异构体到另一个区域异构体突然变化。产品的相对含量是在四个不同的温度下确定的,并假设乘积比代表相对速率比,则可以获得相对活化的焓。从理论上(在B3LYP / 6-31G *理论水平上)考虑了四种不同的中间体。这些中的每一个都经历了角形变以对两个区域异构体建模。在每个变形角处,两个中间体模型之间的能量差与四个中间体中每个中间体的实验数据相关。发现角