We have used Oxone for thioether oxidations in the past, but I am concerned that the acidity of this reagent may cause hydrolysis of our glycosididic bond (we have an acetyl-protected glycoside with a spacer between it and the sulfur). I have seen mCPBA used in a 2005 paper for a very similar transformation; therefore, it would be my first choice. I have also seen dimethyl dioxirane used in a similar reaction. I have also read that Oxone can be buffered with borate (I can provide a reference if anyone is interested). The other oxidants that might be tried are NaWO4•2H2O/H2O2 and KMnO4. My question is why doesn't mCPBA cause cleavage of the glycosidic bond. Is it because the reaction is done under anhydrous conditions?