ABSTRACT
The classical procedure for acetolysis of cellulose was presented in Volume I. Recently, Narui et al.1 reported that addition of tetramethylurea to the reaction mixture allowed the 324use of higher temperatures (80 to 100°C) in acetolysis without inducing irregular degradation and caramelization. The reaction time was thus greatly decreased. For example, acetolysis of a dextran of high molecular weight range (5 to 40 x 106) required 96 h to reach completion at room temperature, but in the presence of 5% of tetramethylurea, acetolysis at 100°C was possible and required only 20 min for completion. Similar results were obtained with amy lose (mol wt 150,000) in the presence of 10% of tetramethylurea. In both cases the product was rich in oligosaccharides of DP 2 to 6, whereas without tetramethylurea the reaction at 100°C produced only D-glucose with isomaltose (dextran) or maltose and maltotriose (amylose), and the mixture was highly caramelized.
