Paclitaxel impurity O

Benzenepropanoic acid, ?- hydroxy- ?- [[ (2E) - 1- oxo- 3- phenyl- 2- propen- 1- yl] amino] - , (2aR, 4S, 4aS, 6R, 9S, 11S, 12S, 12aR , 12bS) - 6, 12b- bis (acetyloxy) - 12- (benzoyloxy) - 2a, 3, 4, 4a, 5, 6, 9, 10, 11, 12, 12a, 12b- dodecahydro- 4, 11-

CC (O[C@]12[C@@]3 ([H]) [C@@H] ([C@]4 (C (C) (C ([C@H] (C ([C@@]3 ([C@H] (C[C@@]1 ([H]) OC2) O) C) =O) OC (C) =O) =C ([C@H] (C4) OC ([C@H] (O) [C@H] (C5=CC=CC=C5) NC (/C=C/C6=CC=CC=C6) =O) =O) C) C) O) OC (C7=CC=CC=C7) =O) =O