3-keto-9-O-substituted oxime derivatives of 6-O-methyl erythromycin A synthesis and in vitro activity

A series of 3-keto-9-O-substituted oxime derivatives of 6-O-methyl erythrom ycin A were prepared with a novel synthetic route, which include 6 reaction steps-oximation, protection, hydrolysis, oxidation, deprotection and addit ion. The antibacterial activity of these compounds were tested in vitro aga inst both erythromycin-susceptible and erythromycin-resistant organisms. Se veral of these derivatives showed improved antibacterial activity against s ome erythromycin-resistant organisms as compared to erythromycin A.