NUCLEOSIDES .9. DIRECT SYNTHESIS OF URACIL NUCLEOSIDES

The direct synthesis of uracil nucleosides results from the reaction of uracil with a glycosyl halide in the presence of mercuric cyanide. In this way, uracil can be converted into N(3)-(2′,3′,4′,6′-tetra-O-acetyl-β-D- glucopyranosyl)uracil (I) and N(1)N(3)-bis-(2′,3′,4′,6′-tetra-O-acetyl-β-D- glucopyranosyl)uracil (III). Either (I) or (III) can be obtained as the main product in high yield by choice of appropriate reaction conditions; (III) is formed from (I) via the N(3)O(6)-bisglucoside (II). A convenient synthesis of 2′,3′,5′-tri-O-acetyluridine illustrates the usefulness of the method.