the invention relates to anhydrides , solvates and ethanol hetero - solvates and hydrates of dimethoxy docetaxel or - 3 - tert - butoxycarbonylamino - 2 - hydroxy - 3 - phenyl - propionate of 4 - acetoxy - 2α - benzoyloxy - 5β , 20 - epoxy - 1 - hydroxy - 7β , 10β - dimethoxy - 9 - oxo - tax - 11 - ene - 13α - yle , and to the preparation thereof .