Ethyl (dimethylsulfurany1idene) acetate has been isolated in 90-95yo yield as an analytically pure liquid and stored successfully for several weeks at-10'; it decomposed slowly at room temperature. Reaction of the ylide with a variety of a, B-unsaturated esters, ketones, aldehydes, and nitriles readily afforded cycloproppl compounds in yields of 40- 90%.
