Dithioketals are converted in good yields to vinyi sulfides by action of diethylzinc and methylene iodide. The reaction has been successfully applied to dialkyl and diaryl dithioketals, to spirocyclic analogs, and to a dithioacetal. A monothioketal produced a vinyl ether (enol ether) with the same reagent.
Alkoxycarbonyl-stabilized ylides from gem-disulfides undergo [2,3]sigmatropic shifts and provided the first entry to betweenanenes with a heteroatom (sulfur) directly attached to the encapsulated olefinic carbon.