Reaction of Dimethyl Phosphonate with Ketene Dimethyl Dithioacetal Derivatives. An Alternative Method to Prepare <i>s</i>-Alkylphosphonates

Abstract

Abstract Reaction of dimethyl phosphonate with phenylketene dimethyl dithioacetal derivatives have been investigated to prepare s-alkylphosphonates. The addition reactions of phosphonate were accelerated in dithioacetal derivatives in the following order: –SMe&amp;lt;–SOMe&amp;lt;&amp;lt;–SO2Me. The reaction of β,β-bis(methylsulfonyl)styrene (7) with dimethyl phosphonate followed by the catalytic reduction afforded dimethyl α-methylbenzylphosphonate in 74% yield from compound 7. The reaction of 1-methylsulfinyl-1-methylthio-4-phenyl-1-butene with dimethyl phosphonate gave dimethyl (2-methylthio-1-phenethylvinyl) phosphonate in 21% yield.