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-dichloro-F-adamantanes, 1,3,5-trichloro-Fadamantane, 1,3,5,7-tetrachloro-F-adamantane, 1-bromo-F-adamantane, and 1-iodo-F-adamantane dissolved in CFCl₃ are conveniently dehalogenated in the presence of methanol, hexane, or other hydrogen donor cosolvents by ultraviolet irradiation. The reactions are very clean with isolated yields in the range of 80 %-90 %. Generally, irradiation times increase when large batches of material are photolyzed and when the less reactive secondary F-adamantyl chlorides are reduced. By controlling the irradiation time, polychloro-F-adamantanes can be reduced in a stepwise manner. Only freeradical, not ionic, products are isolated. A possible mechanism for this photochemical reduction is discussed.