EVIDENCE FOR IONIC INTERMEDIATES IN FLUORINATION OF ALKENES WITH N-F TYPE OF REAGENTS

2-Exo-acetamido-7-syn-fluoro norbornane and 2-exo-acetamido-7-anti-flu oro norbornane were formed in the room temperature reaction of bicyclo [2.2.1]heptene in acetonitrile with N-F type reagents [1-chloromethyl- 4-fluoro-1,4-diazoniabicyclo [2.2.2] octane bis(tetrafluoroborate) (F- TEDA), -fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]octane bis(tetraflu oroborate (NFTh) and 2,6-dichloro-1-fluoro pyridinium triphlate (FPD-T )]. Such Meerwein-Wagner rearrangement and hydride shift indicated the formation of fluoro carbonium ions.