We have developed a concise synthesis of dielsiquinone 1, a potent cytotoxic agent related to anthraquinones. Electrochemical studies have shown that dielsiquinone is reduced to a semiquinone radical that does not react with O-2 to generate toxic reactive oxygen species. These results strongly suggest that I should be less cardiotoxic than anthracyclines used in clinic and may therefore provide the basis for the development of safer anticancer drugs. (c) 2005 Elsevier Ltd. All rights reserved.