Reaction of perfluoroalkanesulfonyl halide: 3. The reactions of perfluoroalkanesulfonyl bromide with α, β-unsaturated esters and chemical conversions of the products

The reactions of perfluoroalkanesulfonyl bromide with α, β-unsaturated esters were studied in detail. The reaction products were further converted to a series of perfluoroalkyl-substituted α, β-unsaturated acids or esters, α-amino acids and γ-lactones. A peculiar peak (M+15) was found to appear in the mass spectra of some perfluoroalkyl-substituted methyl esters. It was interpreted to be the result of a CH₃ group transfer to the molecular ion. Magnetic nonequivalence was observed in the ¹⁹F NMR spectra of CF₂ group linked to CH₂ in compounds 2f, g and 3f, g which showed a typical AB pattern, and was attributed to the effect of steric hindrance.