ALPHA-FLUORO-ALKANALS AND ALPHA,ALPHA-DIFLUOROALKANALS BY SUBSTITUTION OF VICINAL BROMOFLUOROALKANES AND SUBSEQUENT PUMMERER REARRANGEMENT

2-Fluoro- or 2,2-difluoro-1-bromoalkanes readily undergo nucleophilic substitution by sodium thiophenolate to give 2-fluoro- or 2,2-difluoroalkyl phenyl sulfides (1a-1c). The latter may be oxidized to the corresponding sulfoxides (2a - 2c). Heating with acetic anhydride produces 2-fluoro- and 2,2-difluoro-l-(phenylthio)alkyl acetates (3a-3b) which may then be cleaved to give 2-fluoro- and 2,2-difluoro-1-phcnylthio-1-alkanols (5b-5c) or the 2-fluoro- and 2,2-difiuoroalkanals (4a-4c) if not reduced to give 2-fluoro- or 2,2-difluoro-l-alkanols (6b-6c). © 1990.