Reactivity of 1-phenylsulfinyl-2-phenylsulfanyl ethylene (SOSE) with O-nucleophiles generated by potassium tert-butoxide

E-1-Phenylsul.nyl-2-phenylsulfanylethylene (E-SOSE) reacts with O-nucleophiles generated by means of t-BuOK via an addition–elimination mechanism, thus a.ording the product of substitution of the phenylsulfanyl group in a stereo-conservative process. When used alone, the strongly basic and hindered tert-butoxide brings about elimination of either the phenylthiolate or phenylsul.nate groups. Z-SOSE is much more prone to elimination: either with t-BuOK alone or with other O-nucleophiles generated by t-BuOK, it always leads to products derived from elimination. Other alkaline tert-butoxides or other bases appear not as e.ective in generating species nucleophilic enough to react with E-SOSE.