The transformation of cellulose into glucose ester α-d-glucose pentaacetate (GPAc) was carried out in ionic liquid 1-butyl-3-methylimidazolium chloride under mild reaction conditions. The reaction comprises two steps: the first involves a hydrolysis reaction, yielding α-d-glucose and glucose oligomers; and then only after some time, the acetylating reagent acetic anhydride is added. Under optimized conditions and with the acidic resin Amberlyst 15DRY as a hydrolysis catalyst, a 70% yield of GPAc was obtained. This product could be quantitatively isolated by simple liquid-liquid extraction, which allowed easy recycling of the ionic liquid and catalyst.
©2012 by Walter de Gruyter Berlin Boston