Ester thymidine 5 -pyrophosphate

Thymidine 5 -(a-D-glucopyranosyl pyrophosphate) (4) and the analogous D-galactose derivative have been isolated from extracts of Pasteurella pseudo tuberculosis.102 The ester of thymidine 5 -pyro-phosphate with a-D-mannopyranose was found in an extract of Strep-tomyces griseus,14,103 and the occurrence of the D-ribosyl ester in the... 

A mutant strain of Escherichia coli Y-10, defective in L-rhamnose synthesis, accumulates109 a considerable amount of thymidine diphosphate sugars. Three of them were identified110 as the esters of thymidine 5 -pyrophosphate with 6-deoxy-a-D-xyZo-hexopyranos-4-ulose (28), 6-deoxy-D-glucose, and D-fucose. The fourth component was found to be a 4-acetamido-4,6-dideoxy-D-galactose derivative111,112 (29) it occurs also in Pasteurella pseudotuberculosis102 and its... 

Esters of /3-D-mannopyranosyl pyrophosphates have not yet been prepared, and consequently their behavior in alkaline solution is unknown. However, thymidine 5 -(/3-L-rhamnopyranosyl pyrophosphate), in which the steric disposition of groups should be similar in the normal (1C) conformation of the glycosyl group (85), is cleaved readily under alkaline conditions.103... 

Threitol, from polysaccharides, 87 Threonine, 258 Thymidine, 228, 231 6-phosphates, 220 pyrophosphate esters of, 221 5-triphosphoric acid, 228 —, 5-(rhamnosyl dihydrogen pyrophosphate), 219 Thymine, 2-thio-, 229 Thymol, 236... 

Methodology. Filippov has reported a one-pot procedure to prepare phosphate, phosphorothioate and phosphorofluoridate monoesters as well as pyrophosphate monoesters of nucleosides. This versatile approach made use of di(p-methoxybenzyl)-A, A -diisopropylphosphoramidite. While little information was provided on the preparation and stability of the phosphoramidite reagent, its use in the reaction with benzoate-protected thymidine in the presence of dicyanoimidazole as an activator yielded the di(p-methoxybenzyl)phosphite of thymidine [46]. This phosphite could subsequently be oxidised (Scheme 3) to the phenylthioate ester [47a], the phosphate monoesters [47b], the phosphoramidate [47c, d], the phosphorofluoridate [47e], the nitrophenolate diester [47f] and to the fully protected dinucleotide [47g]." ... 

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