Synthesis and Biological Evaluation of 2‐(2‐Deoxy‐β‐<scp>D</scp>‐ribofuranosyl)pyridine‐4‐carboxamide

Abstract A new protected 2‐deoxy‐ D ‐ribose derivative, 5‐ O ‐[( tert ‐butyl)diphenylsilyl]‐2‐deoxy‐3,4‐ O ‐ isopropylidene‐ aldehydo ‐ D ‐ribose ( 5 ), was synthesized starting from 2‐deoxy‐ D ‐ribose. This compound was coupled with 2‐lithio‐4‐(4,5‐dihydro‐4,4‐dimethyloxazol‐2‐yl)pyridine giving a D / L ‐ glycero ‐mixture 7 of 5‐ O ‐[( tert ‐butyl)diphenylsilyl]‐2‐deoxy‐1‐ C ‐[4‐(4,5 ‐dihydro‐4,4‐dimethyloxazol‐2‐yl)pyridin‐2‐yl]‐3,4‐ O ‐isopropylidene‐ D ‐ erythro ‐pentitol. The mixture 7 was 1‐ O ‐mesylated with methanesulfonyl chloride and subsequently treated with CF 3 COOH/H 2 O and ammonia to afford the α/β‐ D ‐anomers 10 of 2‐(2‐deoxy‐ D ‐ribofuranosyl)pyridine‐4‐carboxamide. Both anomers were purified and separated by HPLC and identified by NMR and DCI‐MS. Anomer β‐ D ‐ 10 was evaluated against a series of tumor‐cell lines and a variety of viral strains. No antitumor or antiviral activity was observed.