CHEMICAL MODIFICATION OF THE REDUCING CHAIN END IN DEXTRANS AND TRIMETHYLSILYLATION OF ITS HYDROXYL-GROUPS

The reducing ends of dextrans, of which number-average molecular weights were 3600 and 16000, were almost quantitatively converted to lactone, amine, and acyllactam groups, successively, by iodine oxidation followed by lactonization, aminolysis with 1,4-diaminobutane, and finally reaction with terephthaloylbis (epsilon-caprolactam). Hydroxyl groups in dextrans were also trimethylsilylated for protection with a mixture of 1,1,1,3,3,3-hexamethyldisilazane and trimethylchlorosilane. In advance of every run, the adequate reaction conditions were searched by using D-maltose as a low molecular weight model compound for dextrans.