Unusual Trifluoroacetic Anhydride Promoted Fragmentation of a γ,γ,γ-Trifluoro-β-(p-methoxyphenyl-amino) Sulfoxide†

Abstract

The reaction of a γ,γ,γ-trifluoro-β-(p-methoxyphenylamino) sulfoxide with trifluoroacetic anhydride under Pummerer conditions occurs in an abnormal fashion, providing an excellent yield of the cyclic six-membered sulfonium salt arising from intramolecular interception of the usual trifluoroacetoxy-sulfonium intermediate by the electron rich p-methoxyphenyl group.