methyllithium in the presence of ethyl vinyl ether. A cyclopropane derivative was not obtained from the reaction of 9,9-dibromofluorene (III) or 9,9-dichloro-9H-tribenzo[a.c.e]cycloheptene (IV) with alkyllithium in olefin but 9,9′-bifluorenylidene (IX) and 9,9′-dibromo-9,9′-bifluorenyl (XI) were produced from III and 9-methylene-9H-tribenzo[a.c.e]cycloheptene (XXIII) and 9H-tribenzo-[a.c.e]-cyclohepten-9-ol