Starting from available ribose-building blocks, the 4 '-C-methyl-, 4 '-C-ethyl- and the new 4 '-C- propyl-substituted deoxyuridines were synthesized. Afterwards we converted 4 '-C-alkylated-2'- deoxyuridines into the corresponding 4 '-C-alkylated-5-iodo-2'-deoxyuridines 3a-c and those in turn into the 4 '-C-alkylated-5-iodo-2'-deoxycytidines 4a-c.