Solutions of fluorenylidene carbene (10) have been generated by treatment of 9-(aminomethylene)-fluorene (9) with n-butyl nitrite. This vinylidene carbene forms a 1:1 adduct with azobenzene, and with acetone pivaldehyde and tolualdehyde it forms 1:2 adducts containing the 5-fluorenylidene-1,3-dioxolane ring system. Evidence for the intermediacy of an allene oxide (3) is presented.