Abstract Sodium sulfide and polysulfides readily (50–55° C, 3 h, aqueous medium) react with alkyl vinyl sulfoxides to afford bis (alkylsulfinylethyl) sulfides and-polysulfides in up to 75% yield. Under comparable conditions the reaction of divinyl sulfoxide with sodium sulfide proceeds by the mechanism of addition-cyclization and results in 1, 4-dithiane-1-oxide and 1, 4-oxathiane-4-oxide. Microwave activation of the studied reactions allows to increase ...