Abstract: | Determinations of individual terminal carboxylic acid endgroups and terminal reducing sugar moieties together with analysis of spent liquor revealed that the same reactions occur during treatment of hydrocellulose with hot sodium bicarbonate as with sodium hydroxide solution. Some fragmentation reactions, of little importance in the presence of sodium hydroxide, are favored in bicarbonate medium while benzilic acid rearrangements are less favored. Hence, the formation of 2-dieoxyerythropentonic acid endgroups is more important. Among the soluble reaction products, 3,4-dideoxypentonic acid formed via 3-deoxypentulose and cyclic compounds formed via the same precursor are much more abundant in bicarbonate medium while 3-deoxy-2-hydroxymethylpentonic (isosaccharinic) acids are less abundant. |