Synthesis of some monocyclic-N-acetyl 4′-aza-D-nucleosides

Abstract

1,2,3,5-Tetra-O-acetyl-4-deoxy-4-(acetamido)-β-D-ribofuranose 5 was prepared from L-lyxose, which on condensation with silylated nucleoside bases gave the corresponding protected 4′-azanucleosides. The protecting groups were removed using methanolic ammonia to afford the N-acetyl-4′-azanucleosides, wherein the sugar ring oxygen is replaced with a substituted nitrogen atom, in good yields. Further, the 1-(4-deoxy-4-acetamido-β-D-ribofuranosyl)thymine 16 was transformed to the corresponding 2′-deoxy, 2′,3′-dideoxy derivatives. The stereochemical assignments of the synthesized nucleosides were established based on NMR and X-ray studies.