作者:F.G. Riddell、M.J.T. Robinson
DOI:10.1016/s0040-4020(01)98146-3
日期:1971.1
preferred orientations of ethyl and isopropyl groups in 1-alkyl-3,3-diphenylallenes and in 2-alkyl-1,3-dioxanes and -dioxolanes have been determined from the temperature dependence of the spin-spin coupling constants for appropriate vicinal protons. In the allenes a methyl group rather than a hydrogen atom eclipses a double bond but in the cyclic acetals skew interactions between methyl groups and oxygen
由自旋-自旋偶合质子的自旋-自旋偶合常数对温度的依赖性确定了1-烷基-3,3-二苯基丙烯以及2-烷基-1,3-二恶烷和-二氧戊环中乙基和异丙基的优选取向。在丙二烯中,甲基而不是氢原子会覆盖双键,但是在环状缩醛中,甲基和氧原子之间的偏斜相互作用在优选的构型中被最小化。结论是简单的酮和醛中的构象偏好主要取决于双键而不是羰基的氧原子的电负性。