Derivatives of fluorine-containing 3-(methoxycarbonylmethylthio)acrylic acids readily undergo base-catalyzed cyclization to form 3-hydroxy- and 3-aminothiophenes.
A new method was developed for the synthesis of fluorine-containing functionally substituted vinyl sulfides and ketene dithioacetals from the corresponding derivatives of a-trifluoromethyl-substituted CH-acids and thiols in the presence of BF(3) . NEt(3).