Uridine 5 -phosphate, chemical synthesis

Synthesis of sucrose 6 -phosphate by an enzymic method using uridine 5 -(a-D-glucopyranosyl diphosphate) plus D-glucose 6-phosphate has been reported.126-131 The first, unambiguous, chemical synthesis of sucrose 6 -phosphate was achieved by Buchanan and coworkers.18 The reaction of 2,3,4,6,l, 3, 4 -hepta-0-acetylsucrose, prepared by five steps of synthesis, with cyanoethyl phosphate in pyridine gave a crude product from which sucrose 6 -phosphate was isolated as the barium salt. 

The unambiguous chemical synthesis of adenylic acid a by phosphorylation of 3, 5 -di-0-acetyladenosine has been achieved. Subsequently, uridine 2 -phosphate was synthesized from 3, 5 -di-0-acetyluridine, and was shown to be identical with uridylic acid a. Justifiably, the "a and b designations for these isomeric nucleotides have now been abandoned, and have been replaced by the positional designations, namely, nucleoside 2 - and 3 -phosphates. 

The chemical synthesis of uridine 5-(a-D-glucopyranosyl pyrophosphate) has been effected by condensing a-n-glucopyranosyl phosphate with uridine 5-phosphate in the presence of dicyclohexylcarbodiimide. The yield of glycosyl nucleotide in this reaction is very low, primarily because dicyclohexylcarbodiimide promotes the formation of n-glucose cyclic 1,2-phosphate in preference to the formation of the pyrophosphate bond. In an improved synthetic method, the nucleotide is first converted to a phosphoramidate (5) or phosphoromorpholidate (6), by condensation in the presence of dicyclohexylcarbodiimide with ammonia or morpholine, respectively. 

Chemical Synthesis.—Purine nucleoside 5 -monophosphates enriched with or 0 on the phosphate group are conveniently prepared by treating phosphorus pentachloride in dry triethyl phosphate with one equivalent of the appropriately labelled water to give PO]- or P 0]P0Cl3, which is not isolated but mixed with adenosine or guanosine in the same solvent. Work-up of the resulting 5 -phos-phorodichloridate in similarly labelled water permits the formation of pO]-or P 0]AMP (or GMP) in fair yield with good enrichment. The 5 -monophos-phates of the 5 -C-methyl uridines derived from 6-deoxy-D-allose and 6-deoxy-L-talose have been prepared via phosphorylation of the 2, 3 -0,0-ethoxymethyl-idene derivative of the nucleosides (1) with -cyanoethyl phosphate and DCC or TPS-Cl. The same method has been used to phosphorylate iV -benzoylated 2, 3 -0,C -isopropylidene derivatives of various 5 -C-alkyladenosine species (2) and also 4 -allyladenosine (3) as part of a study in which derivatives of AMP... 

Hexokinase catalysed syntheses of 6-amino-6-deoxy-D-glucose and -D-gluconate 6-phosphates, 6-amino-6-deoxy-D-fructose 6-phosphate and 1,6-bisphosphate, and 5-amino-5-deoxy-D-ribulose 5-phosphate have been reported. From a study of the properties and reactivity in enzymic reactions of these compounds, it was concluded that they were excellent isosteric analogues of the normal metabolic intermediates except for reactions catalysed by kinases. A preparative enzymic synthesis of uridine 5 -diphospho-2-acetamido-2-deoxy-D-glucose used chemically synthesized 2-acetamido-2-deoxy-D-glucose 1-phosphate and uridine triphosphate as reactants, and a calf liver enzyme extract containing uridine-5 -phospho-A-acetylglucosamine pyrophosphorylase. ... 

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