作者:A. Pons、J.P. Chapat
DOI:10.1016/0040-4020(80)80115-3
日期:1980.1
The equilibration of the cis and trans isomers of four epimeric pairs of 3,4-dialkyl cyclohexanones (alkyl = Me, Et) have been studied quantitatively at different temperatures. The thermodynamic constants ΔH and Δs exhibit considerable variations depending on the nature (Me or Et) of the substituents. These quantities were also calculated from statistical considerations. Theoretical and experimental
已经在不同温度下定量研究了4个3,4-二烷基环己酮对映异构体对的顺式和反式异构体的平衡(烷基= Me,Et)。热力学常数ΔH和Δs根据取代基的性质(Me或Et)表现出相当大的变化。这些数量也是从统计考虑因素计算得出的。理论值和实验值一致。当甲基被乙基取代时,观察到的变化的起因是由于其他可能的构象异构体中位阻的增加,导致了双轴构象异构体比例的增加。通过反式-3,4-二烷基环己酮肟的NMR研究在实验上证实了这一点。