3′-C-Trifluoromethyl-β-D-ribonucleoside derivatives bearing the fivenaturallyoccurringnucleicacidbases have been synthesized. All these derivatives were prepared by glycosylation reactions of purine and pyrimidine bases with a suitable peracylated 3-C-trifluoromethyl ribofuranose precursor. After deprotection, the resulting title nucleoside analogues were tested for their inhibitory properties against