PHOTOCHEMICAL REDUCTION OF F-ADAMANTYL HALIDES - A FACILE SYNTHESIS OF HYDRYLFLUOROCARBONS FROM CHLOROFLUOROCARBONS

1-Chloro- and 2-chloro-F-adamantanes, 1,2- and 1,3-dichioro-F-adamanta nes, 1,3,5-trichloro-F-adamantane, 1,3,5,7-tetrachloro-F-adamantane, 1 -bromo-F-adamantane, and 1-iodo-F-adamantane dissolved in CFCl3 are co nveniently dehalogenated in the presence of methanol, hexane, or other hydrogen donor cosolvents by ultraviolet irradiation. The reactions a re very clean with isolated yields in the range of 80%-90%. Generally, irradiation times increase when large batches of material are photoly zed and when the less reactive secondary F-adamantyl chlorides are red uced. By controlling the irradiation time, polychloro-F-adamantanes ca n be reduced in a stepwise manner. Only free-radical, not ionic, produ cts are isolated. A possible mechanism for this photochemical reductio n is discussed.