Fig. 7 in Discovery of a stable vitamin C glycoside in crab apples (Malus sylvestris)

Fig. 7. Acetylation of 2 under basic conditions gave the unsaturated glycoside 8, but acidic conditions led to the successful acetylation of both 2 and 2a. I. Ac2O, pyridine, 0 ̊C, overnight, 44%. II. Ac2O, HClO4, 0 ̊C, 1 h, 71% (9) and 73% (9a) yield.