Synthesis and Antibacterial Activity of Isomeric 15-Membered Azalides

A series of 3-keto and 3-O-acyl derivatives of both 6-O-alkyl-8a-aza-8a-homoerythromycin A and 6-O-alkyl-9a-aza-9a-homo-erythromycin A were synthesised and tested against Gram-positive and Gram-negative bacteria. Derivatives of 8a-aza-8a-homoerythromycin A have potent antibacterial activity against not only azithromycin-susceptible strains, but also efflux (M) and inducible macrolide-lincosamide-streptogramin (iMLSB) resistant Gram-positive...