Methanesulfonic anhydride (I) and ethanesulfoiiic anhydride (11), chosen as reasonably representative alkanesulfonic anhydrides, were prepared from the corresponding acids by means of phosphorus pentoxide. I and 11, as well as p-toluenesulfonic anhydride (111), were also prepared from the corresponding sulfonyl chlorides by the use of metallic oxides. I reacts more rapidly than does methanesulfonyl chloride (IV) in sulfone formation with ...
