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The Thorpe–Ingold effect, gem-dimethyl effect, or angle compression is an effect observed in chemistry where increasing steric hindrance favours ring closure and intramolecular reactions.
Apr 24, 2017 · 概要 偕二甲基效应，又称Thorpe-Ingold效应。 当一个亚甲基上的氢被两个甲基取代后就形成了一个偕二甲基碳。 两个甲基相互推搡的结果是增大了两者之间的键角，同时缩小了构成碳四面体的另一对键的键角，于是相连基团之间就被推得近了一点。
偕二甲基效应，又称Thorpe-Ingold效应，由Richard M. Beesley、Christopher K. Ingold与Jocelyn F. Thorpe于20世纪初发现，指有机物中亚甲基碳连接两个甲基时，空间排斥导致键角变化：内键角变小，邻近基团空间接近从而加速环化反应。
Sep 15, 2014 · PDF | The Thorpe-Ingold effect and its advances in both theoretical and experimental studies are introduced briefly.
In addition to taking advantage of the Thorpe–Ingold effect through the use of gem -dialkyl-substituted cyclooctanoid systems, we have also preliminarily explored the use of analogous gem -dimethoxy derivatives.
有机反应中的偕二甲基效应（Thorpe-Ingold效应）,偕二甲基效应，又称为Thorpe-Ingold效应，即当分子链中亚甲基上的氢被大体积烷基取代后， 该处键角变小，分子链末端两个反应基团相互靠近，有利于分子内环化反应。
本文首先介绍了Thorpe-Ingold效应及其相关理论和实验研究进展，然后综述了近年来Thorpe-Ingold效应在形成三、四、五和六元环产物的环化反应中的应用。 Thorpe-Ingold效应可以有效地促进分子内和分子间环化，提高环化的产率和速率。
The Thorpe-Ingold effect and its advances in both theoretical and experimental studies are introduced briefly. Its recent applications in cyclizations for formations of three-, four-, five-, and six-membered ring prod...
With other rings, substituents reduce the number of conformations that can form that would not lead to a ring, making ring formation more likely based upon entropy. Key Words: ThorpeIngold, Enthalpy, Entropy, Ring Formation
Continuing the work begun by Beesley, Ingold’s first paper with Thorpe soon followed. They proposed that two sterically demanding substituents would move apart, beyond the ideal tetrahedral ...
