The Oxidation of S ‐Acetyl by Nitrite: Mechanism and Application

Straightforward S‐S bond formation via the oxidation of S ‐acetyl group by nitrite was observed and the mechanism was explored in this study. The observed reaction was found to be initiated via a S ‐nitrosylation followed by the S‐S bond formation that accompanies nitrite oxide (NO) release. The reaction approach was further analyzed by quantum chemical studies, surpporting a mechanism of first generating nitrous ester. Unlike S ‐nitrosylation between thiols and nitrite proceeding at a strong alkaline condition due to the formation of hydroxyl anion, the S ‐nitrosylation between S ‐acetyl and nitrite proceed at a condition close to neutrality due to the formation of acetate instead. Using this reaction, per‐ O ‐acetylated glycosyl disulfides were obtained in high yields at mild condition. Furthermore, per‐ O ‐acetylated glycosyl 1‐thiols were also efficiently prepared starting from per‐acetylated 1‐thio‐glycoses in a one‐pot reaction including the oxidation of S ‐acetyl group by nitrite and the reduction of disulfides.