This randomized phase II trial is studying how alvocidib, cytarabine, and mitoxantrone hydrochloride work compared to cytarabine and daunorubicin hydrochloride in treating patients with newly diagnosed acute myeloid leukemia. Alvocidib may stop the growth of cancer cells by blocking some of the enzymes needed for cell growth. Drugs used in chemotherapy, such as cytarabine, mitoxantrone hydrochloride, and daunorubicin hydrochloride work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. It is not yet known whether giving alvocidib, cytarabine, and mitoxantrone hydrochloride is more effective than giving cytarabine and daunorubicin hydrochloride in treating patients with acute myeloid leukemia.