117136-35-3

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-pentofuranose 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 characterized by elemental analyses and UV and 1H-NMR spectra.

Various 3'-deoxy pyrimidine nucleoside analogues have been synthesized for evaluation as potential anticancer and antiviral agents.Among these compounds, 1-(3-deoxy-β-D-threo-pentofuranosyl)cytosine (10, 3'-deoxy-ara-C) and 3'-deoxycytidine (22) had significant anticancer activity against CCRF-CEM, L1210, P388, and S-180 cancer cell lines in vitro, producing ED50 values of 2,10,5,and 34 μM, respectively, for 3'-deoxy-ara-C (10); and 25, 5, 2.5, and 15μM, respectively, for 3'-deoxycytidine (22).Thus, 3'-deoxy-ara-C (10) was 12.5 times more active against CCRF-CEM cells than 3'-deoxycytidine (22).The 2'-O-acetyl, 5'-O-acetyl, and 2',5'-di-O-acetyl derivatives of 3'-derivatives of 3'-deoxy-ara-C (10), compounds 34, 31, and 30, demonstrated anticancer activity in the same range as 3'-deoxy-ara-C (10) against CCRF-CEM, L1210, P388, and S-180 cells.The 5'-O-acetyl derivative (31) had significantly greater activity against CCRF-CEM with an ED50 value of 0.4 but this compound also showed similar activity, as did 3'-deoxy-ara-C against L1210, P388, and S-180 with ED50 values of 3, 3, and 13 μM, respectively. 3'-Deoxy-ara-C was also evaluated in vitro against HSV-2, HCMV, and GPCMV viruses and was found to be not very active with respective IC50 values of 110, 220, and 1000 μM.The single-crystal structure of 3'-deoxy-ara-C (10) was determined by X-ray crystallography.There are two molecules of the nucleoside and one molecule of water in the asymmetric unit.The sugar moieties of two nucleoside molecules adopt different conformations.In molecule A, the ring pucker is C3'-endo with P=18.7 deg and τm= 37.3 deg, while the CH2OH side chain is gauche+.In molecule B, the ring pucker is C2'-endo with P= 156.8 deg and τm = 37.8 deg and the side chain is trans.