Ceric Ammonium Nitrate / Acetic Anhydride: A Tunable System for the O-Acetylation and Mononitration of Diversely Protected Carbohydrates

Esterification of a wide range of partially protected carbohydrate derivatives was achieved using acetic anhydride and a catalytic amount of ceric ammonium nitrate. Compatibility with the commonly used protecting groups was demonstrated, with the esterified products being furnished in good yields. Apart from affording the O-acetylated products, their mononitrated counterparts were also produced depending upon the reactivity of the starting material. Decreasing the molar equivalents of CAN afforded the O-acetylated products exclusively, while increasing it favored the mononitrated derivatives.