Fluorinateddi-enes may be obtained by the defluorination of some oligomers of F-alkenes and -cycloalkenes using tetrakis(dimethylamino)ethene. These di-enes are very susceptible to nucleophilic attack. Nucleophilic epoxidation of (4) gives a new diepoxide which undergoes a novel ring-opening reaction. Di-ene (4) forms cyclopentadienylide derivatives with di-functional carbon nucleophiles and a cyclopentadienylide