A Diastereoselective Synthesis of 5′-Substituted-Uridine Derivatives

A straightforward strategy for the synthesis of 5′-substituted-uridine derivatives is described. It relies on the introduction of various substituents at C-5′ at the last step of the synthesis by regioselective nucleophilic opening of a unique epoxide that provides access to a small library of compounds. This epoxide results from the diastereoselective epoxidation, performed at a multigram scale, of a uridine-derived alkene. The configuration of the newly created 5′ asymmetric center has been unambiguously assigned by X-ray diffraction analysis.