Abstract: The fragmentation process of cycloolefino [b] pyrrole in EI MS and FAB MS have been studied. It was that hydrogen rearrangement by initiation of radical-site and loss of ketenes, occur to form 2-ethyl formate-3-hydroxy-cycloolefino [b] pyrrole ions, followed by loss of an ethanol by ortho effect, loss of CO, and reducing pyrrole ring formed by loss of CO or HCN. Furthermore Retro-Diels-Alder reaction occur for some of cyclohexeno [b] pyrrole derivatives.

Key words: cycloolefino [b] pyrrole, hydrogen rearrangement, ortho effect, loss of alcohol, Retro-Diels-Alder reaction

摘要： 环烯并吡咯衍生物在EI和FAB条件下，可以发生游离基引发的氢重排失去一个中性的烯酮型分子，生成3-羟基-2-甲酰乙酯环烯并吡咯，后者由于邻位效应，又失去一分子乙醇、CO及发生缩环和一系列吡咯环的裂解反应。一些环己烯并吡咯衍生物的离子可以发生RDA反应。

关键词: 环烯并吡咯, 氢重排, 烯酮类化合物, 邻位效应, 失醇, 逆Diels-Alder反应