Mercaptans P 0430Synthesis and Reactivity of Fluorine-Containing Thiols and Thioacyl Halides. -Thermal splitting of polyfluoroalkyl benzyl sulfides like (I) in the presence of P 2 O 5 provides access to the free thiols (II). The latter are used in further transformations to demonstrate their synthetic utility. In contrast, thermal splitting of 1,1-dichloropolyfluoroalkyl benzyl sulfides, e.g. (XII), as well as α,β-unsaturated benzyl sulfides like (XX) affords thioacyl halides [(XIII), (XXI)]. Their reactivity is also studied in several transformations. -(SIZOV*, A. Y.; KOVREGIN, A. N.; SERDYUK, R. N.; VOROB'EV, M. V.; POROSYATNIKOV, V. A.; TSVETKOV, A. A.; KORNEEV, D. O.; ERMOLOV, A. F.; Russ.