- SYNTHESIS OF 5'-O-β-D-GLUCOPYRANOSYL AND 5'-O-β-D-GALCTOPYRANOSYL DERIVATIVES OF RIBAVIRIN
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The synthesis of 5'-O-β-D-glucopyranosyl and 5'-O-β-D-galactopyranosyl derivatives (13 and 15, respectively) of the antiviral agent ribavirin are described.Direct glycosylation of 2',3'-O-isopropylideneribavirin with either tetra-O-acetyl-α-D-glucopyranosyl bromide (4) or tetra-O-acetyl-α-D-galactopyranosyl bromide (8) under Koenigs-Knorr conditions (i.e., silver carbonate, silver perchlorate, and Drierite in dichloromethane) followed by O-deacetylation of the reaction product gave the corresponding ortho esters.However, treatment of 2',3'-di-O-acetyl-5'-O-tritylribavirin (11) with 4 under the Bredereck modification of the Koenigs- Knorr reaction (i.e., silver perchlorate and Drierite in nitromethane) and subsequent deacetylation furnished the desired 1-(5-O-β-D-glucopyranosyl-β-D-ribofuranosyl)-1,2,4-triazole-3-carboxamide (13).Similarly, reaction of 11 with 8 in the presence of AgClO4, and deprotection of the condensation product, gave 5'-O-β-D-galactopyranosylribavirin (15).The β-anomeric configuration of the D-glucosyl and D-galactosyl groups of 13 and 15 was assigned by (1)H-n.m.r. studies.
- Hanna, Naeem B.,Robins, Roland K.,Revankar, Ganapathi R.
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p. 267 - 274
(2007/10/02)
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