| abstract |
The present invention refers to compounds of formula: (formula A), wherein R 1 is selected from (formula I), (formula II), (formula (III), (formula IV), (formula V), or (formula B), and wherein R 2 , R 3 , R 4 and R 5 are as defined in the claims and X is OTBS, hydroxy, formyloxy, acetoxy, nitrooxy, nitrooxymethyl, or a halogen; and pharmaceutically acceptable salts thereof, which are useful in the treatment of neoplastic or proliferative disorders, a pharmaceutical composition comprising such a compound and a method preparing this compound. |