Influence of steric and polar effects in determining the equilibrium position for <i>cis</i>–<i>trans</i>-olefin pairs
作者:D. V. Gardner、D. E. McGreer
DOI:10.1139/v70-349
日期:1970.7.1
substituted by t-butyl or isopropyl groups at the β-position along with methoxyl, thioethoxyl dimethylamino, chloro, and hydrogen at the other β-position have been prepared. Evaluation of the isomer stability from cis-trans equilibrations achieved catalytically or thermally supports earlier observations'that steric and polar factors maintain a strong tendency for a β-methoxyl group to be trans to a nitrile or
一系列α,β-不饱和腈和酯在β-位被叔丁基或异丙基取代,在另一个β-位被甲氧基、硫代乙氧基二甲氨基、氯和氢取代。从催化或热上实现的顺反平衡对异构体稳定性的评估支持早期的观察结果,即空间和极性因素保持β-甲氧基转为腈或甲氧基的强烈趋势,即使与叔丁基相反团体。通过用异丙基或叔丁基代替 β-甲基,可以克服在 β-氯巴豆酸甲酯中氯基团优先与碳甲氧基基团反式的趋势。