A novel regio- and stereospecific hydrohalogenation reaction of 2-propynoic acid and its derivatives
摘要:
2-Propynoic acid and its derivatives are hydrohalogenated regio- and stereospecifically by reaction with lithium halides in acetic acid, or preferably with 1 equiv of acetic acid in refluxing CH3CN, to afford the thermodynamically unfavorable (Z)-3-halopropenoic acids and their derivatives as sole products. A rationale for the regio- and stereospecificity is briefly discussed.
A novel regio- and stereospecific hydrohalogenation reaction of 2-propynoic acid and its derivatives
作者:Shengming Ma、Xiyan Lu、Zhigang Li
DOI:10.1021/jo00028a055
日期:1992.1
2-Propynoic acid and its derivatives are hydrohalogenated regio- and stereospecifically by reaction with lithium halides in acetic acid, or preferably with 1 equiv of acetic acid in refluxing CH3CN, to afford the thermodynamically unfavorable (Z)-3-halopropenoic acids and their derivatives as sole products. A rationale for the regio- and stereospecificity is briefly discussed.
Microwave Spectra and Molecular Structures of (<i>Z</i>)-Pent-2-en-4-ynenitrile and Maleonitrile
作者:Robert J. Halter、Ryan L. Fimmen、Robert J. McMahon、Sean A. Peebles、Robert L. Kuczkowski、John F. Stanton
DOI:10.1021/ja011195t
日期:2001.12.1
Accurate equilibrium structures have been determined for (Z)-pent-2-en-4-ynenitrile (8) and maleonitrile (9) by combining microwave spectroscopy data and ab initio quantum chemistry calculations. The microwavespectra of 10 isotopomers of 8 and 5 isotopomers of 9 were obtained using a pulsed nozzle Fourier transform microwave spectrometer. The ground-state rotational constants were adjusted for vibration-rotation
通过结合微波光谱数据和 ab initio 量子化学计算,已经确定了 (Z)-pent-2-en-4-炔腈 (8) 和马来腈 (9) 的准确平衡结构。使用脉冲喷嘴傅里叶变换微波光谱仪获得了 8 种同位素的 10 种和 9 种同位素的 5 种的微波光谱。基态旋转常数根据从 ab initio 计算获得的力场计算的振动-旋转相互作用效应进行了调整。所得的平衡旋转常数用于确定与从高级 ab initio 计算 (CCSD(T)/cc-pVTZ) 获得的结构非常一致的结构。8和9中的几何参数非常相似;它们也与全碳类似物 (Z)-hex-3-ene-1,5-diyne (7) 没有显着差异,伯格曼环化的母体分子。观察到 7-9 和几个相关物种的炔烃和氰基键的线性偏差很小,其中有准确的平衡参数可用。7-9 的数据应该对射电天文学感兴趣,并且可以提供对不饱和物质(如氰基多炔)的形成和星际化学的见解。