In connection with the pericyclic reaction of 3, 5-dimethylpyridine N-oxide with N-substituted maleimides, the structure of a 1, 5-sigmetropy product was determined by the X-ray crystallographic method. In the reaction of 2-alkylpyridine N-oxides with N-substituted maleimides, we have isolated a series of 1 : 3 ene reaction products of a new type.The primary exo cycloadducts readily transform into the endo 1, 5-sigmatropic rearrangement products, which again react with two molecules of N-substituted maleimide to give the 1 : 3 ene reactio products. The observed reaction behavior and plausible reaction pathways are discussed in terms of frontier molecular orbital considerations.
                                    与3, 5-二
甲基吡啶N-氧化物与N取代马来
酰亚胺的周环反应相关,通过X射线晶体学方法确定了一种1, 5-σ迁移产物的结构。在2-烷基
吡啶N-氧化物与N取代马来
酰亚胺的反应中,我们分离出一系列新型的1:3烯反应产物。初级外向环加成物易于转化为内向1, 5-σ迁移重排产物,这些产物又与两个N取代马来
酰亚胺分子反应,生成1:3烯反应产物。观察到的反应行为和可能的反应路径通过前沿分子轨道理论进行了讨论。