Abstract: The present invention relates to the preparation of taxane derivatives starting from 10-deacetyl-baccatine III, 14-hydroxy-10-deacetyl-baccatine 111, 19-hydroxy-10-deacetyl-baccatine III and their esters at C.sub.13, reacting the respective 10-dehydro derivatives with hydrazine, hydroxylamine and derivatives thereof. The novel compounds contain a pyrazoline group involving the C.sub.7 and C.sub.9 carbons. The C.sub.13 esters of these molecules with substituted isoserine chains exert antitumor activity inhibiting cell proliferation of normal and resistant tumor cell lines and inducing apoptosis. These molecules due to their basic character can be administered upon salification in an aqueous medium without requiring the use of toxic surfactants.