A series of anomeric 2-phenyl-1,2,3-osotriazole C-nucleoside analogs Summary: has been prepared. The anomeric configuration was determTned by a novel method from the chemical shiftofthec-5 protonoftheosotriazole base moieties. J-Nucleoside analogs are useful tools for biochmical investigations and for antimitotic or antiviral research'. The carbon-carbon linkage between the glycosyl and base moieties, makes these compounds more stable towards acid and enzymatic cleavage, than lj-nucleosides. A satisfactory method for synthesis is by dehydration of the hydroxyalkyl chain of C-(hydroxyalklated) nitrogen heteracyclic derivatives by use of a strong acid 2:5 . This method has not been extensively used because of the uncertainty of their anomeric configuration6. In the present work 2-phenyl-1,2,3_osotriazole &-nucleoside analogs having the Q-lyxo-, D-arabino-, and D-ribo-furanosyl configuration were prepared from =their precursors 3,6-anhydro-heptulose phenylosazones by cyclization of the bis-(phenylhydrazone) residues with copper sulphate. Dehydration of P-galacto-heptulose phenylosrone with methanolic sulphuric acid solution 899 , then refluxing the product with copper sulphate, (Scheme 1), gave the anomeric mixture 4-(6-Plyxofuranosyl)-Gphenyl-1,2,3-osotriazole band 4-(a-g-lyxofuranosyl)-2-phenyl-1,2,3-osotriazole 5, in 52% overall yield, they were separated by fractional crystallization. Compound 1; m.p. 125", [ali + 4.3' (C 2.4,methanol), high resolution mass spectrum showed m/e 277.105 (Cal. for C,3H,5N304; 277.106). UV (methanol) X max 265 nm (log E 4.4). Compound $; m.p. 204O, [ali + 51' (C 0.4, methanol), highresolutionmassspectrumshowedm/e277.106(calc. 277.106). UV (methanol)
x max 266nm(logc4.3).