Regio- and Stereoselective Synthesis of Functionalized Vinyl Sulfides Based on Pyridine-2-thiol and Propynoic Acid and Its Derivatives

Regio- and stereoselective methods of synthesis of 3-(pyridin-2-ylsulfanyl)prop-2-enoic acid and alkyl (Z)-3-(pyridin-2-ylsulfanyl)prop-2-enoates have been developed on the basis of nucleophilic addition of pyridine-2-thiol to propynoic acid and alkyl propynoates. Reactions of alkyl (Z)-3-(pyridin-2-ylsulfanyl)prop-2- enoates with methyl iodide afforded 2-[(3-alkoxy-3-oxoprop-1-enyl)sulfanyl]-1-methylpyridinium iodides.