Hydrazones of aldehydes and ketones undergo intermolecular cycloaddition to electronegative olefins via azomethine imines, formed by a formal 1,2-prototropic shift, in low to moderate yield on heating in xylene or ethanol. In some instances the reaction is diverted to give products derived (at least formally) from an ene reaction. Similar intramolecular cycloadditions occur with unactivated terminal
醛和酮的dra通过在正式的1,2-质子转移反应中形成的偶氮甲
亚胺,在二
甲苯或
乙醇中加热时,产率低至中等,从而发生分子间环加成反应。在某些情况下,使反应转向以产生(至少正式地)衍生自烯反应的产物。未活化的末端烯烃和
炔烃也会发生类似的分子内环加成反应。