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 (ϵ‐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 search by using D ‐maltose as a low molecular weight model compound for dextrans.