Synthetic studies on amino-α-glycosides of aminocyclitols. Synthesis of kanamycin analogues

A diastereoisomer of Kanamycin C has been synthesized by a modified Koenigs—Knorr reaction of 3,4,6-tri-O-acetyl-2-(2,4-dinitroanilino)-2-deoxy-α-D-glucopyranosyl bromide with 4-O-(3-acetamido-2,4,6-tri-O-benzyl-3-deoxy-α-D-glucopyranosyl)-N,N′-di(benzyloxy)carbonyl]-2-deoxystreptamine. Several Kanamycin analogues were synthesized by a similar condensation reaction. Each of the condensed products was isolated as its crystalline tetra-N-acetyl derivative and was proved by n.m.r. spectroscopy in D₂O to have the α-configuration.