Ethyl (Dimethylsulfuranylidene)acetate (EDSA) is used ad a stabilized sulfonium ylide reagent capable of reacting with a variety of electrophiles to produce substituted
cyclopropanes, epoxides, enamines, and stabilized ylides, as well as other products.[1]
Preparative Method of Ethyl (Dimethylsulfuranylidene)acetate: synthesized in two simple steps (85% overall yield). An equimolar combination of ethyl
bromoacetate and Dimethyl Sulfide is stirred in acetone at rt for three days, after which the precipitated
sulfonium salt is isolated by filtration. The salt is then converted to the ylide by treatment with K2CO3/NaOH in
CHCl3/water.[1b]
although Ethyl (Dimethylsulfuranylidene)acetate is subject to moisture-induced and thermal
decomposition, no report of hazard has been found. The presence of water gives rise to ester hydrolysis and
quenching of the ylide to form the zwitterionic sulfonium carboxylate Me2+SCH2CO2
-. Significant instability
has also been noted at slightly elevated temperatures (35% decomposition at 80 °C in 3 h). Successful storage
(several weeks) can be accomplished at -10 °C under anhydrous conditions.[1b]
1. (a) Speziale, A. J.; Tung, C. C.; Ratts, K. W.; Yao, A. JACS 1965, 87, 3460. (b) Payne, G. B. JOC 1967, 32, 3351. (c)
Payne, G. B. JOC 1968, 33, 1284. (d) Payne, G. B. JOC 1968, 33, 1285. (e) Payne, G. B. JOC 1968, 33, 3517.
