1-(alkylsulfinyl- and -alkylsulfonyl)-2-(F-alkyl)ethynes - Applications incycloaddition reactions and synthesis of aromatic derivatives

Syntheses and cycloaddition reactions of 1-(alkylsulfinyl-and -alkylsulfony l)-2-(F-alkyl)ethynes are described, These alkynes are strong dienophiles a nd produce the corresponding F-alkylated sulfinyl- and sulfonylbenzenes in two high-yielding steps. When treated under basic conditions, the (F-alkyl) cyclohexadienyl adducts were converted into a mixture of the same aromatic compounds and the corresponding alpha -defluorinated derivatives, by way of a competitive oxidation/(HF) elimination on the deprotonated intermediates .