C-Glycosyl 1,2,4-triazoles: Synthesis of the 3-β-d-glucopyranosyl-1,5-disubstituted and 5-β-d-glucopyranosyl-1,3-disubstituted variants

Highly variable synthetic routes were elaborated toward trisubstituted C-glycopyranosyl 1,2,4-triazoles. N-Acyl-thioamide derivatives were obtained by acylation of O-perbenzoylated 2,6-anhydro-d-glycero-d-gulo-heptonothioamide by acid chlorides and of thioamides by O-perbenzoylated 2,6-anhydro-d-glycero-d-gulo-heptonoyl chloride. These precursors reacted with substituted hydrazines in a regioselective manner to yield 3-β-d-glucopyranosyl-1,5-disubstituted- and 5-β-d-glucopyranosyl-1,3-disubstituted-1,2,4-triazoles, respectively. Analogous N-acyl-2,6-anhydro-heptonamides failed to give the above triazoles with hydrazines. O-Deprotection of the C-glucosyl 1,2,4-triazoles by the Zemplén method furnished test compounds which showed no inhibition against rabbit muscle glycogen phosphorylase b.

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