研究了二溴卡宾与取代苯乙酮的反应机理．在取代苯乙酮与二溴卡宾的反应中，由于形成的羰基叶立德中间体的非平面构象，使得１，３－偶极加成难以发生，其主要反应途径为电环化和脱氧反应的竞争．当增大苯环上取代基的供电子能力时，原处于次要地位的脱氧反应的程度有所增强，但变化程度有限，故不能代替电环化成为主要反应 The reaction mechanism of dibromocarbene and substituted acetophenone was studied. In the reaction of substituted acetophenone with dibromo-carbene, 1,3-dipolar addition is difficult to occur due to the non-planar conformation of the carbonyl ylide intermediate formed. The main reaction pathway is the competition between electrocyclization and deoxygenation reactions . When increasing the electron-donating ability of substituents on the benzene ring, the degree of deoxidation which was originally in the secondary position is enhanced but the degree of change is limited, so it can not replace the electrocyclization as the main reaction