Preparation of C-5-substituted 6,5′-O-anhydrouridine by Sn–Pd transmetallation-coupling process and their use

The palladium-catalyzed reaction of 5-tributylstannyluridine derivative (9) with a variety of aryl, vinyl halides provides an efficient method for the synthesis of the corresponding 5-substituted 6,5′-O-anhydrouridines. Additionally the 5-fluoro 6,5′-O-anhydrouridine (16) via fluoro-destannylation with Selectfluor is described. A dialkylphosphonate moiety was then introduced at C5 from the allyl derivative 10a under cross-metathesis conditions.