Synthesis of 2‐carbamoylmethyl‐6‐β‐D‐ribofuranosylpyridine with the aid of a Pd(0)‐catalyzed reaction

D‐Allo/D‐altro‐2‐(2,4:3,5‐di‐O‐benzylidenepentitol‐l‐yl)‐6‐ethoxycarbonylmethylpyridine was synthesized from 2‐bromo‐6‐(2,4:3,5‐di‐O‐benzylidenepentitol‐1‐yl)pyridine or 2‐(2,4:3,5‐di‐O‐benzylidenepentitol‐1‐yl)‐6‐iodopyridine by means of a tetrakis(triphenylphosphine)palladium(O)‐catalyzed reaction with Reformatsky's reagent. Subsequent ammonolysis and mesylation of the D‐altro‐ethoxycarbonylmethyl compound gave D‐altro‐2‐carbamoylmethyl‐6‐(1‐O‐mesyl‐2,4:3,5‐di‐O‐benzylidenepentitol‐l‐yl)pyridine which was cyclized to 2‐carbamoylmethyl‐6‐β‐D‐ribofuranosylpyridine.