The present invention relates to the synthesis of 2'-deoxy-.beta.-L-thymidine, 2'-deoxy-.beta.-L-uridine and 2'-deoxy-.beta.-L-cytidine, and their derivatives, such as the 3'-O-acyl or 3',5'-O-diacyl prodrugs, including the 3'-O-L-aminoacyl and 3',5'-O-L-diaminoacyl prodrugs, and particularly the 3'-O-L-valinyl and 3',5'-O-L-divalinyl prodrugs.