On irradiation with (E)-anethole in benzene 10-hydroxymethyl-9-phenanthrenecarboxylic acid lactone (s-trans lactone, STL) gave an intermolecular [2+2] cycloadduct, a cyclobutane derivative, while 8-hydroxymethyl-9-phenanthrenecarboxylic acid lactone (s-cis lactone, SCL) afforded a cyclobutane derivative and an olefinic product derived from an oxetane precursor, the carbonyl adduct. The formation of cycloadducts of highly different structures in SCL was ascribed to competitive collapse of the involved exciplex to the products. The features of intermolecular cycloaddition of the phenanthrene derivatives are discussed on the basis of results obtained from molecular orbital calculations.
在苯中用(E)-
茴香脑照射10-羟甲基-9-
菲甲酸内酯(s-顺式内酯,SCL)可得到一种分子间[2+2]环加成物,即
环丁烷衍
生物,而8-羟甲基-9-
菲甲酸内酯(s-反式内酯,STL)则得到
环丁烷衍
生物和由氧杂
环丁烷前体衍生的烯烃产物,即羰基加合物。由于涉及的激发复合体竞争性崩解为产物,SCL形成了结构高度不同的环加合物。基于分子轨道计算结果,讨论了
菲衍
生物分子间环加成的特征。