Stereoselective Synthesis of the C-4 Linked Imidazole Nucleosides Using Modified Mitsunobu Reaction

Article abstract of DOI:10.1016/0040-4039(95)00503-5

A highly stereoselective synthesis of the novel 4-(β-D-ribofuranosyl)imidazole 5 was accomplished in 4 steps and 85 percent overall yield from protected D-ribose 1.Cyclization of the diol (RS)-3 having an intact imidazole by modified Mitsunobu reaction exclusively afforded benzylated β-ribofuranosylimidazole β-4a, accompanied by α-4a, in a ratio of 26:1.Reductive debenzylation completed the synthesis. 2'-Deoxy derivative 8 was also synthesized stereoselectively in the same manner.