Alkaline degradation of fructofuranosides

The degradation of fructose with aqueous Ca(OH)2 gives products similar to the same reaction with glucose. The fructofuranosyl linkage in glycosides cleaves at 130–140°C and the fructose so released degrades to products that are different in proportion to those from free fructose under similar reaction conditions. Non-reducing glycopyranosides are resistant to alkaline degradation at lower temperatures, methyl α-d-glucopyranoside and α,α′-trehalose at even 250°C. For purposes of comparison, the alkaline degradation of glucose, lactose, and xylose was also studied. The relative contributions of the intermediate enediols to the reaction pathways are discussed.