Ad irect route to chiral pyrimidine acyclic nucleoside analogues with as ulfur-containing side chain is reported via enantioselective tandem conjugated addition-protonation reactions of thioacetic acid to a-pyrimidine substituted acrylates. In the presence of aq uininederived thiourea catalyst, diverse chiral sulfur-containing pyrimidine acyclic nucleoside analogues could be obtained in excellent yields (95-99%)a nd with moderate to excellent enantioselectivity values (up to 99 % ee).