1984 Volume 32 Issue 4 Pages 1441-1450
N4-Benzoyl-2'-deoxycytidine (1) was converted to its 3', 5'-di-O-acetate (2). Compound 2 was smoothly anomerized to its α-counterpart (3) by reaction with trimethylsilyl trifluoromethanesul-fonate (TMS-triflate). Saponification of 3 afforded crystalline α-2'-deoxycytidine (4). Similarly, 3', 5'-di-O-p-toluoyl-2'-deoxythymidine (5) was anomerized to the α-anomer (6), which was then deblocked to give α-2'-deoxythymidine (7). α-2'-Deoxyadenosine (8) and 9-(2-deoxy-α-D-ribofuranosyl)-6-methylthiopurine (9a) were prepared by TMS-triflate-catalyzed trans-2-deoxyribosylation from compound 2 to N6-benzoyladenine and 6-methylthiopurine, respectively. α-5-Fluoro-2'-deoxycytidine (11a) and its β-anomer (11b) were synthesized by the reaction of the trimethylsilyl derivative of N4-p-toluoyl-5-fluorocytosine with 1-O-acetyl-3, 5-di-O-benzoyl-2-deoxy-D-ribofuranose followed by deblocking. Among the compounds related to α-2'-deoxyribonucleosides, compound 4 and 11a showed weak growth-inhibitory activity on mouse leukemic L5178Y cells in culture. Of the nucleoside 5'-triphosphates, α-deoxy ATP had some affinity with DNA polymerase α when activated DNA was used as a template-primer. α-Deoxythymidine 5'-triphosphate (TTP) showed a remarkable inhibitory effect on DNA polymerase β when poly [rA]-oligo dT was used as template-primer.
