Nucleosides. LVI¹ Synthesis and Chemical Modifications of 3′-Deoxy-Pyrimidine Nucleosides

Abstract

3′-Deoxyuridine(1) and 3′-deoxycytidine(2) were prepared with improved yields by two different methods applying either the Barton procedure to appropriate 2′, 5′-di-O-protected pyrimidine nucleosides or by choosing the direct glycosylation of the pyrimidine bases with 1, 2-di-O-acetyl-5-O-toluoyl-3-deoxy-D-erythro-opentofuranose via the silylation approach. Suitable protecting groups for the sugar moiety have been found in the trityl, tert-butyldimethylsilyl and the thexyl groups which are inert in the radical deoxygenation process. The newly synthesised compounds were characterised by elemental analyses and UV and ¹H-NMR spectra.