Comparison of stereopopulation control with conventional steric effects in lactonization of hydrocoumarinic acids
Comparison of stereopopulation control with conventional steric effects in lactonization of hydrocoumarinic acids
复制标题
氢化香豆酸内酯化反应中立体布居控制与常规空间效应的比较
DOI：
10.1021/ja00430a045
复制
发表时间：
1976
影响因子：
15
通讯作者：
C. Wilcox
中科院分区：
文献类型：
--
作者：
R. Winans;C. Wilcox
Milstein和Cohen观察到，在酸催化的氢香豆素酸内酯化反应中，通过将立体相互作用的甲基取代到酸上，其速率有了特别大的提高。他们将这些速率的增加解释为立体种群控制（构象锁定），而不是传统的基态应变缓解。用经验力场模型估计常规立体应变释放的重要性，得出常规应变释放是主导因素的结论。介绍了计算模型，并对计算结果进行了详细分析。
Milstein and Cohen have observed exceptionally large rate enhancements in the acid-catalyzed lactonizationof hy-drocoumarinic acid on substitution of sterically interacting methyl groups to the acid. They have interpreted these rate in-creases in terms of stereopopulation control (conformational locking) rather than a conventional ground state relief of strain. Estimation of the importance of conventional steric strain relief by a empirical force field model leadsto the conclusion that the conventional strainrelief is the dominant factor. The calculational model is described and the results are analyzed in some detail.