Taxane derivatives of formula (I) in which: R is trifluoromethyl, phenyl, 2-furyl, 2-thienyl; R.sup.1 is t-butoxycarbonyl or benzoyl; R.sub.2 is hydroxy; R.sub.3 is hydrogen or, together with R.sub.2, it forms the residue of a cyclic carbonate of formula: II with the proviso that when R3 is hydrogen, R is different from phenyl. Compounds of formula (I) have antitumor activity ##STR00001##