Chemical modification of aminocyclitol antibiotics

The aminocyclitol antibiotic neamine has been chemically modified at the hydroxyl group on C-6 of the 2-deoxystrepatamine moiety. The partially acetylated neamine derivatives, 6,3,4-tri-O-acetyl- (3) and 5,3-57,4-tri-O-acetyl-1,3,2,6-tetra-N-(ethoxycarbonyl)neamine (4), were prepared by random hydrolysis of the 5,6-O-ethoxyethylidene derivative (2), followed by chromatographic purification. Condensation of 4 and 2,3,5-tri-O-benzoyl-D-ribofuranosyl chloride led to 6-O-(beta-D-ribonfuranosyl)neamine (7). Analogous condensation of 4 with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide or 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide afforded the corresponding 6-O-(D-hexopyranosyl)neamines.