Thermal Disrotatory Electrocyclic Isomerization of <i>cis</i>-Bicyclo[4.2.0]oct-7-ene to <i>cis,cis</i>-1,3-Cyclooctadiene
作者:John E. Baldwin、Sarah S. Gallagher、Phyllis A. Leber、Anuradha Raghavan
DOI:10.1021/ol040022g
日期:2004.4.1
[reaction: see text] The ratio of observed rate constants, k/k', for thermal isomerizations of cis-bicyclo[4.2.0]oct-7-ene and its 2,2,5,5-d(4) analogue to cis,cis-1,3-cyclooctadienes at 250 degrees C is 1.17, indicative of a secondary, not a primary, deuterium kinetic isotope effect. The reaction does not occur through a [1,5] hydrogen shift from the transient cis,trans-1,3-cyclooctadiene intermediate
[反应:见正文]顺式-双环[4.2.0] oct-7-ene及其2,2,5,5-d(4)热异构化反应的观察到的速率常数k / k'的比率250℃下顺式,顺式-1,3-环辛二烯的顺式为1.17,表示继发的而不是主要的氘动力学同位素效应。通过从瞬态顺式,反式-1,3-环辛二烯中间体发生[1,5]氢转移以形成观察到的顺式,顺式-二烯产物,不会发生反应。