1,2,3 triazole carbohydrates

Ribavirin Ribavirin, l-j3-D-ribofuranosyl-l//-l,2,4-triazol-3-carboxamide (36.1.28), is synthesized by reacting methyl ester of l,2,4-triazol-3-carboxylic acid with 0-l,2,3, 5-tetraacetyl-j3-D-ribofuranose to make methyl ester of l-0-2,3,5-tetraacetyl-j3-D-ribofura-nosyl-l,2,4-triazol-3-carboxylic acid (36.1.27), which is treated with an ammonia solution of methanol to simultaneously dezacylate the carbohydrate part and amidation of the carboxyl part of the product to give ribavirin [29-37]. 

Zinc chloride-doped natural phosphate was shown to have catalytic behavior in the 1,3-dipolar cycloadditions of nucleoside acetylenes with azides to form triazolonucleosides <99SC1057>. A soluble polymer-supported 1,3-dipolar cycloaddition of carbohydrate-derived 1,2,3-triazoles has been reported <99H(51)1807>. 2-Styrylchromones and sodium azide were employed in the synthesis of 4(5)-aryl-5(4)-(2-chromonyl)-1,2,3-triazoles <99H(51)481>. Lead(IV) acetate oxidation of mixed bis-aroyl hydrazones of biacetyl led to l-(a-aroyloxyarylideneamino)-3,5-dimethyl-l,2,3-triazoles <99H(51)599>. Reaction of 1-amino-3-methylbenzimidazolium chloride with lead(fV) acetate afforded l-methyl-l/f-benzotriazole <99BML961>. Hydrogenation reactions of some [l,2,3]triazolo[l,5-a]pyridines, [l,2,3]triazolo[l,5-a]quinolines, and [l,2,3]triazolo[l,5-a]isoquinolines were studied <99T12881>. 

Dedola S, Hughes DL, Nepogodiev SA et al (2010) Synthesis of a- and ) -D-glucopyranosyl triazoles by CuAAC click chemistry Reactant tolerance, reaction rate, product structure and glucosidase inhibitory properties. Carbohydr Res 345 1123-1134... 

Peto, C, Batta, G, Gydrgydeak, Z, Sztaricskai, E, Glycoside s3mthesis with anomeric l-A-glycobiosyl-l,2,3-triazoles, 7. Carbohydr. Chem., 15,465-483, 1996. 

A library of glycoconjugate benzenesulfonamides that contain carbohydrate-triazole units has been evaluated for their ability to inhibit three human transmembrane carbonic anhy-drase isoz5mies hCA IX, hCA XII and hCA XIV which have potential as dmg targets OFig. 73 [118]. 

These glycosides can be prepared by inserting the carbohydrate moiety into a suitable pyrimidine or triazole nucleus, followed by ring closure (see Section IV). However, the sugar residue is often introduced into a preformed 8-azapurine nucleus, and four principal methods are available. These may be termed the sieves, fusion, mercuric, and classic methods. 

Fig. 4-3b). Reaction of azides and alkynes in the presence of catalytic Cul proceeded regioselectively in 8 hours to give a 1,3-dipolar cycloaddition product (i.e., 1,4-disubstituted 1,2,3-triazole) in good yield, whereas thermal cycloaddition gave a mixture of 1,4- and 1,5-disubstituted 1,2,3-triazole. The Cu(I)-catalyzed reaction was applied successfully to fabricate carbohydrate arrays in microtiter plates [45-47]. 

The term C-nucleoside was only coined after isolation and characterization of the first member of this class pseudouridine, in 1975 [97ACH(ip)]. Before that, alditolyl derivatives of some heterocycles (acyclo C-nucleo-sides) were known both as natural products (alditolyl pteridines or biopterins) as well as products of syntheses (e.g., alditolyl derivatives of imidazoles, benzimidazoles, thiazoles, benzothiazoles, 1,2,3-triazoles, quinoxalines, and flavazoles) and were classified as carbohydrate derivatives of heterocyclic compounds. After isolation of pseudouridine, other naturally occurring members were successively isolated, characterized, and synthesized. It is worth mentioning that synthesis preceded isolation in two cases 9-dea-zaadenosine and pyrrolosine. Comparison with the synthetic compounds facilitated structure elucidation in one case (9-deazaadenosine) and structure reassignment in the other (pyrrolosine). 

Recently, however, several such assays have been developed for the study of carbohydrate-enzyme interactions. As mentioned previously, carbohydrate microarrays can be employed for inhibitor identification. Indeed, they were recently used by Wong and coworkers to identify fucosyltransferase inhibitors from a small library (85 compounds) of triazole-containing compounds [46,... 

Unlike the glycosides, which are readily hydrolyzed, carbohydrate arylosotriazoles have the sugar residue firmly bound and are imaffected by acids or alkalis. It was thus possible to convert the aminophenyloso-triazoles into dyestuffs" which reacted with cellulose fibers treated with cyanuric chloride the dyes then acquired considerable fastness. 

Eldehpield, Robert C., The Carbohydrate Components of the Cardiac Glycosides, 1, 147-173 El Khadem, Hassan, Chemistry of Oso-triazoles, 18, 99-121... 

In related work, the same group prepared a series of trifluoromethyl-substituted 1,2,3-triazoles linked to D-galactose and D-gulose by the cycloaddition of 1 -phenyl-2-trifluoromethyl acetylene to the carbohydrate-linked azide.In this case, both regioisomeric triazoles were formed. The procedure is exemplified by the reaction with the galactose-derived azide 163 to give the carbohydrate-linked triazoles 164 and 165 (Fig. 3.94). 

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