Synthesis of Oligosaccharides Containing 2-Acetamido-2-deoxyxylose by Chemical and Enzymic Methods

0-2-Aoetamido-2-deoxy-ß -D-glucopyranosyl-(l→-4)-5-^3H-2-aoetamido-2-deoxy-D-xylopyranose (1) was pre-pared from the ß(l→4)-linked A-acetylglucosamine dimer (2) by formation of the diethyl dithioacetal (3), glycol cleavage with periodate, reduction with ^3H-NaBH4, and dithioacetal hydrolysis. 1 was isolated by charcoal-Celite column chromatography. A by-product, 0-2-acetamido-2-deoxy-ß -D-glucopyranosyl-(l→-4)-5-³.ff-2-acetamido-2-deoxy-L-arabmopyranose, was isolated as well. 1 was also isolated from the lysozyme-catalyzed reaction of the A⁷-acetylglucosamine tetramer with 5-³-H-2-acetamido-2-deoxy-a-D-xylopyranose (10), demonstrating the structure of 1 and supporting a 0(l→4) linkage for the higher oligomers containing N-acetyl-xylosamine and two or three N-acetylglucosamine residues, which were also produced in the enzymic reaction.