5'-Deoxy-4', 5-difluorouridine (4'-F-5'-dFUrd)(10) has been synthesized on the basis of the rationale that the labilization of the glycosidic linkage caused by the 4'-flUOrO substituent might allow this compound to be a better prodrug form of the anticancer drug 5-fluorouracil (FUra) than is the widely studied fluoropyrimidine 5'-deoxy-5-fluorouridine (5'-dFUrd). The rate of solvolytic hydrolysis of the glycosidic linkage of 4'-F-5'-dFUrd at pH 1 was about ...