Etodolac EP Impurity C

Erythromycin A Enol Ether ; (2R, 3R, 4S, 5R, 8R, 9S, 10S, 11R, 12R)-9-[(2, 6-Dideoxy-3-C-methyl-3-O-methyl-?-L-ribo-hexopyranosyl)oxy]-5-ethyl-3, 4-dihydroxy-2, 4, 8, 10, 12, 14-hexamethyl-11-[[3, 4, 6-trideoxy-3-(dimethylamino)-?-D-xylohexopyranosyl]oxy]-6, 15-dioxabicyclo[10.2.1]pentadec-1(14)-en-7-one ;