Generation of F-Alkyl-substituted Vinyl Thionium Ion Intermediates and Their Reaction with Silyl Enol Ethers. A New Route to δ-F-Alkyl-α,β;γ,δ-unsaturated Carbonyl Compounds

Abstract

Abstract Treatment of 3-F-alkyl-3-fluoro-2-propenyl phenyl or ethyl sulfoxide with trimethylsilyl triflate and a hindered amine produces the corresponding vinyl thionium ion species, which readily reacts with silyl enol ethers to give δ-F-alkylated γ,δ-unsaturated carbonyl compounds. These compounds are converted into δ-F-alkyl-α,β;γ,δ-unsaturated carbonyl compounds in good yields.