Abstract: A process for the preparation of compounds of the formula: ##STR1## wherein Pg and R are protecting groups and B is a nucleobase. The process uses protected nucleobases to form 2,2'-anhydro nucleosides having the formula ##STR2## which are hydrolyzed to 2'-hydroxy intermediates which are then oxidized to the desired 2'-keto compounds. The compounds and intermediates are useful as antiviral and antitumor agents and as intermediates to 2,2'-anhydro-1-(.beta.-D-arabinofuranosyl)cytosine (anhydro-ara-C) and 1-.beta.-D-arabinofuranosylcytosine (Ara-C).