5"-Amino-3',4',5"-trideoxybutirosin A, a new semisynthetic aminoglycoside antibiotic

5"-Amino-3',4',5"-trideoxybutirosin A (IX) was synthesized through a reaction series starting from 5"-amino-5"-deoxybutirosin A (Ic), the key step being the treatment of its tetra-O-acetylpentakis-N-((phenylemthoxy)carbonyl)-3',4'-bis-O-(methylsulfonyl) derivative (VI) with zince-sodium iodide. Compound IX inhibits enhanced antibacterial activities, including strains of Pseudomonas aeruginosa and Escherichia coli which are highly resistant to Ic, butirosin or gentamicin.