Generation of new dithia dications from sterically congested 1,9-dithiodibenzothiophenes and their monooxides in concentrated sulfuric acid

Article abstract of DOI:10.1016/S0040-4039(00)91655-1

1,9-Dithiodibenzothiophenes 2 were prepared by ring contraction of 4,6-dithiothianthrene-5-oxides with n-butyllithium. Both compounds 2 and their monooxides 3 upon dissolution in conc. H₂SO₄ afforded the corresponding new dithia dications. Electrochemical oxidation of 2 provides the evidence for the neighboring group interaction between the two 1,9-sulfenyl sulfur atoms.