Abstract: Compounds having the general formula (I), ##STR1## wherein X and Y represent individually H or --NO, at least one of them being a group-NO, n is 0, 1 or 2, R represents hydrogen, an aliphatic, cycloaliphatic, cycloaliphatic-alkyl, aryl or aralkyl radical, or a group of formula, ##STR2## wherein R.sub.1 is a lower alkyl radical or an aryl, all these radicals being optionally substituted. The present invention also relates to the compounds hereabove defined in the form of mixtures of their position isomers. Furthermore, the present invention discloses processes for preparing such compounds, as well as compositions, useful particularly in anticancerous chemotherapy, containing at least one of said compounds as an active principle.