Reaction of cyclic ketones 2–6 and imines 15–17 in HF/SbF5 in presence of CCl4 yield hydroxy or fluoroderivatives, hydride abstraction occurring at a site located far from the functional group. Whereas ketones 2–5 yield only hydroxy derivatives, through cyclic carboxonium ion, imines 15, 16 N-protonated in the media conditions give only fluoroderivatives 18, 19, respectively, after quenching with HF–pyridine. Ring contraction ...
