Abstract: Compounds of the formula ##STR1## wherein R.sup.1 is a hydrogen atom or a hydroxyl group; R.sup.2 is a hydrogen atom or a hydroxyl or methoxyl group; X is a fluorine, chlorine, bromine or iodine atom; one of Y and Y' is a hydrogen atom and the other is a hydrogen atom or a hydroxyl or acyloxy group; R.sup.3 and R.sup.4 are each independently a hydrogen atom, an alkyl group, a halo- or phenyl-substituted alkyl group, an acyl group or a halo- or phenyl-substituted acyl group or R.sup.3 and R.sup.4 together form a polymethylene chain having 4 to 6 carbon atoms, are useful as anti-tumor agents, especially for treating leukemia; in particular these compounds exhibit high antileukemic activity against P388 murine leukemia.