“…On the basis of the excellent leaving ability of poly(per)fluorosulfonate anion (in comparison with p-toluenesulfonate anion) 6 and the ease of reaction of poly(per)fluoroalkanesulfonyl fluoride with alcohol in the presence of a base, we have studied the reaction of HCF 2 CF 2 OCF 2 CF 2 SO 2 F (an easily available compound in our hand) with threo-diol and hydrogen peroxide (H 2 O 2 ), respectively, in the presence of an organic or inorganic base, resulting in the smooth formation of enantiopure cis-epoxide and in situ generation of highly efficient oxidant polyfluoroalkanesulfonic peracid. 5o,p With these findings in hand and as a continuation of our project of poly(per)fluoroalkanesulfonyl fluoride-mediated reactions and their application in synthetic organic chemistry, we envisaged that the reaction of HCF 2 CF 2 OCF 2 CF 2 SO 2 F with carboxylate anion would produce the unstable mixed anhydride (intermediate A in Scheme 1) which would be easily attacked by a nucleophile such as an alcohol, an amine or a carboxylic acid anion, resulting in the formation of an ester, amide or anhydride (Scheme 1).…”