Abstract: A C-nucleoside compound, 2,4-dichloro-5-(2,3,5-Tri-O-acetyl-.beta.-D-Ribofuranosyl)pyrimidine, useful as a primary starting material in the synthesis of various C-nucleoside compounds having antitumor, antiviral and/or antibacterial activity. A structural formula is as follows: ##STR1## The location of the 2,4-dichloro members on the heterocycle, with the active sites of the carbohydrate being blocked, provides an intermediate compound well adapted for a variety of nucleophilic substitutions. Such procedures have yielded several novel analogs of known pyrimidine nucleosides found in RNA, as well as other compounds which have demonstrated chemotherapeutic utility.