OBJECTIVES: I. Determine the maximum tolerated dose of DX-8951f in patients with advanced myelodysplastic syndromes, refractory acute myeloid or lymphocytic leukemia, refractory or transformed chronic lymphocytic leukemia, or chronic myelogenous leukemia in blastic phase. II. Evaluate the quantitative and qualitative toxic effects of this regimen and determine the duration and reversibility of these effects in these patients. III. Make a preliminary determination of the antileukemic activity of this regimen in these patients. IV. Evaluate the pharmacokinetics of this regimen in these patients.