DISEASE CHARACTERISTICS: One of the following hematologic malignancies: Advanced myelodysplastic syndromes Refractory anemia with excess blasts Refractory anemia with excess blasts in transformation Chronic myelomonocytic leukemia Refractory acute myeloid leukemia (AML) First salvage with primary refractory AML or first complete response (CR) no greater than 12 months in duration or at least second salvage therapy Once maximum tolerated dose is determined, intermediate AML prognosis (first CR duration greater than 12 months but less than 24 months) eligible Refractory acute lymphocytic leukemia Refractory or transformed chronic lymphocytic leukemia Chronic myelogenous leukemia in blastic phase No CNS disease