Abstract
Treatment of 5-(methylamino)-1-β-D-ribofuranosylimidazole-4-carboxamide (5a) with CNBr in acetate buffer gave the 5-cyanomethylamino derivative 6a, which was cyclized to 3-methyl-guanosine (7) in the presence of NaOEt. Cyclocondensation of 7 with bromoacetone in the presence of K2CO3 provided 3-β-D-ribofuranosylwye (2), the most probable structure for the fluorescent nucleoside from Torulopsis utilis phenylalanine transfer ribonucleic acid (tRNAPhe). The glycosidic bonds of 2 and 7 have been shown to be unusually subject to cleavage under either acidic or basic conditions, but proved to be less labile under neutral conditions, as had been reported. The base moiety of 2 is also cleaved under basic conditions.
