The thermal cycloaddition reaction of 1-ethoxycarbonyl-1H-1, 3-diazepines (4a, b) with 2, 5-dimethyl-3, 4-diphenylcyclopentadienone (5) gave three kinds of 1 : 1 cycloadducts, exo [6+4]π (6), syn-endo [4+2]π (7), and anti-endo [4+2]π (8) cycloadducts, the structures of which were elucidated by spectral analyses and the following photochemical study. Irradiation of the [4+2]π cycloadducts 7 and 8 resulted in an intramolecular [2+2]π cycloaddition to afford the cage compounds 12 and 13, respectively, while the [6+4]π cycloadducts (6), upon irradiation, underwent a retro-reaction to give the bicyclic compounds (11), presumably via the parent 1, 3-diazepines (4).
1-乙氧羰基-1H-1,3-二氮杂卓(4a,b)与
2,5-二甲基-3,4-二苯基环戊二烯酮(5)的热环加成反应产生了三种1:1的环加成物,即外[6+4]π(6)、顺-内[4+2]π(7)和反-内[4+2]π(8)环加成物,其结构通过光谱分析和以下光
化学研究得以阐明。[4+2]π环加成物7和8的照射导致分子内[2+2]π环加成,分别得到笼状化合物12和13,而[6+4]π环加成物(6)在照射后发生逆反应,通过母体1,3-二氮杂卓(4)得到
双环化合物(11)。