12-O-Methyl Clarithromycin

(3R,4S,5S,6R,7R,9R,11R,12R,13S,14R)-6-[(2S,3R,4S,6R)-4-(dimethylamino)-3-hydroxy-6-methyloxan-2-yl]oxy-14-ethyl-12-hydroxy-4-[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-7,13-dimethoxy-3,5,7,9,11,13-hexamethyl-oxacyclotetradecane-2,10-dion;