Paclitaxel Impurity-E

[(1S,2S,3R,4S,7R,9R,10S,12R,15S)-4,12-diacetyloxy-15-[(2R,3S)-3-benzamido-2-hydroxy-3-phenylpropanoyl]oxy-1,9-dihydroxy-10,14,17,17-tetramethyl-11-oxo-6-oxatetracyclo[11.3.1.03,10.04,7]heptadec-13-en-2-yl] benzoate; 7-Epitaxol; 7-epi-Taxol; Epitaxol; 7-Epipaclitaxel; (2aR ,4R ,4aS ,6R ,9S ,11S ,12S ,12bS )-9-(((2R ,3S )-3-Benzamido-2-hydroxy-3-phenylpropanoyl)oxy)-12-(benzoyloxy)-4,11-dihydroxy-4a,8,13,13-tetramethyl-5-oxo-3,4,4a,5,6,9,10,11,12,12a-decahydro-1H -7,11-methanocyclodeca[3,4]benzo[1,2-b]oxete-6,12b(2aH )-diyl diacetate (USP)