Abstract
1, 6-Anhydro-2, 3, 3'-tri-O-benzyl-4', 6'-O-benzylidene-β-maltose (5), a maltose derivative having only one unprotected hydroxyl group at the C-2' position, was synthesized from 1, 6-anhydro-4', 6'-O-benzylidene-2'-O-tosyl-β-maltose (2) by benzylation followed by removal of the tosyl group with base. Compound 5 was converted into the corresponding ulose (7) by dimethylsulfoxide (DMSO)-Ac2O oxidation. Treatment of 7 with hydroxylamine gave the 2'-oxime (9). Reduction of 9 with LiAlH4 in ether and subsequent N-acetylation gave protected 1, 6-anhydro-β-N-acetyl-glucosaminylglucose (12) and -mannosaminylglucose (13) in a yield ratio of ca. 6 : 1. Debenzylidenation followed by debenzylation of 12 or 13 gave 1, 6-anhydro-β-N-acetyl-glucosaminylglucose (17) or-mannosaminylglucose (19). The title sugar was obtained was white prisms by acetolysis of the 1, 6-anhydro-β-linkage of peracetylated 17, followed by de-O-acetylation.
