reactions between carbohydrates and cyclic1,3-dicarbonylcompounds do not produce 1,8-dioxooctahydroxanthenes in general, reaction strategies have been devised to generate new 1,8-dioxooctahydroxanthene C-nucleosides by reacting sugars masked with acid-labile protecting groups and with free hydroxyl groups with 1,3-cyclohexanedione or dimedone. Some of these compounds are more cytotoxic to the cancer