Pathways in the reactions of nitronate ions with sulphonyl halides

Primary and tertiary nitronate ions and sulphonyl bromides and iodides rapidly equilibrate with the nitrohalides and sulphinate ion. Products are determined by solvent and by the occurrence of cross-equilibrium reactions, some of which have single-electron-transfer mechanisms. The reaction of arene-sulphinate and -thiolate ions with 1,2-dibromo-2-nitro-1-phenylethane gave E-β-nitrostyrene by Z-philic elimination in both cases, but the more basic thiolate ion also gave, by protophilic elimination, 2-bromo-2-nitro-1-phenylethene.