SYNTHESES OF ANOMERIC PAIRS OF NEW C-NUCLEOSIDES VIA 1,3-DIPOLAR CYCLOADDITION REACTION .2.

1,3-Dipolar cycloaddition of dipolarophiles (1) and (2) with endocycli c heterocyclic azomethine ylides (4), (14) and (24), prepared in situ, leads to the protected beta-and alpha- C-nucleosides (7), (8), (17), (18), (27) and (28), respectively. These, on subsequent hydrolysis, pr ovide the corresponding C-nucleosides. The structures of all the synth esized compounds are confirmed through analytical and spectral data. T he assignment of configuration at C-1' position of the C-nucleosides c ould be done by a comparative study of the properties of the correspon ding alpha and beta anomers with a reasonable degree of certainity.