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DOI: 10.1055/s-1991-26369
A Useful Horner Reagent for the Synthesis of Some α-Methyl-α,β-Unsaturated S-Propyl Thioesters
Publication History
Publication Date:
17 September 2002 (online)

S-Alkyl 2-(dialkoxyphosphoryl)alkanethioates 3 can readily be prepared by the reaction of 2-(dialkoxyphosphoryl)alkanoyl chlorides 1 with thiols 2 in the presence of triethylamine. Only S-propyl 2-(dialkoxyphosphoryl)propanethioate (3b) gave synthetically useful Horner reactions: it was converted into the α-potassiopropanethioate anion by treatment with potassium carbonate in a small amount of water at room temperature. The Horner reaction between this anion and aldehydes 4 gave various α,β-unsaturated thioesters 5 with an α-substituted methyl group. Application of this method to the cis/trans ethyl 2-formyl-3,3-dimethyl-1-cyclopropylcarboxylate esters 4f led to the 2-(propylthiocarbonyl)-2-propenyl pyrethroid derivatives 5f.