Erythromycin A cyclic 11,12-carbonate; (1R,2R,5R,6S,7S,9R,11R,13R,14R)-8-[(2S,3R,4S,6R)-4-Dimethylamino-3-hydroxy-6-methyloxan-2-yl]oxy-2-ethyl-9-hydroxy-6-[(2R,4R,5S,6S)-5-hydroxy-4-methoxy-4,6-dimethyloxan-2-yl]oxy-1,5,7,9,11,13-hexamethyl-3,15,17-trioxabicyclo[12.3.0]heptadecane-4,12,16-trione
