5 - Methenedibenzo [ a, e ] - cycloheptane and 5 - Methylenedipyridine [ 2,1 - b ： 3,4 - b＇ ] - cyclopentane were synthesized by two different methods. One method was that ketones react with methyhriphenylphosphonium bromide （wittig reaction） to give target products （2a and 2b）. Another method was that Grignard reagent （methylmagnesium iodide） was used as nucleophilic reagent to react with ketones, then H2SO4 was dropped to eliminate H20 and the products（2a and 2b） were obtained. The latter way was better than the anterior way because...
