The Reactions of Sulfur Ylides with Cyclic Carboxyl Compounds and Isocyanates

Abstract

Abstract It was found that the reactions of dimethyloxosulfoniummethylide (II) with cyclic carboxyl compounds (I), such as lactones, carboxylic anhydrides and imides, gave the corresponding stable oxosulfonium ylides (III). In addition, the reaction of phenyl isocyanate dimer (IX) and dimethylsulfoniummethylide (X) afforded a 1:1 adduct (XI), which, on heating, decomposed to give a ring expansion product (XIV). Hydantoin derivatives (XVII) were also produced by treating dimethylsulfonium-α-methylacylmethylide (XVI) with two moles of isocyanates in dimethyl sulfoxide. On the other hand, when the same reactions were carried out in benzene, XVI reacted with an equimolar amount of isocyanates to give acrylamide derivatives (XVIII) in high yields by the rearrangement of the intermediate sulfoniummethylide (XX).