Phosphates and Related Esters of Nucleosides

Syntheses of the adenosine and guanosine 5 -phosphoroazidates (622) and (613), which were required as affinity labels, of P -di([ C]adenosine-5 )penta-phosphate, an inhibitor of adenylate kinase (E.C. 2.7.4.3), and, by improved procedures, of 3 -deoxyadenosine (cordycepin) 5 -triphosphate have been reported. 2 -Deoxy-2 -deuterio-adenosine (276) (see p. 100) and its 2 -epimer have been converted into the corresponding 3, 5 -phosphates, whose conformers were examined by H n.m.r. spectroscopy.  

The increase in the number of papers on nucleoside phosphates over the past year has been matched by an increase in the number of phosphorylating agents used these reagents could be used with other carbohydrates as well as with nucleosides. 

High yields (80—98%) of the corresponding 5 -phosphates were obtained when nucleosides reacted with a mixture of phosphoryl chloride, water, and pyridine (2 1 2) in acetonitrile the active phosphorylating agent was identified as an 

BrokeS and J. Berdnek, Coll. Czech. Chem. Comm., 1975, 40, 3061. 

Ki a Y. Taguchi and Y. Mushika, Chem. and Pharm. Bull. Japan), 1975, 23, 1586. 

B = cytosin-l-yl, adenin-9-yl, guanin-9-yl, etc. Reagents i, ROPOsHa-DCC-DMF ii, AcOH-py (high dilution) 

8-5 -anhydronucIeoside (489) has been converted into the corresponding 2, 5 -phosphate, which gave 9-(3-deoxy-j8-D-er tAro-pentofuranosyl)adenine (cordycepin) 2, 5 -phosphate (490) on desulphurization with Raney nickel.An improved synthesis of /3-hydroxyethyl esters of nucleoside 5 -phosphates was 

3 -(Adamant-l-yl)phosphonates have been prepared from 5 -deoxy-5 -halogenouridines and 6-azauridine (see Vol. 9, p. 162).  

The a- and jS-D-arabinofuranosyl and a- and jS-o-xylofuranosyl nucleotide analogues [(493) and (494), respectively] and the 2-bromo derivative (495) of 5-amino-l-j3-D-ribofuranosylimidazole-4-carboxyIic acid 5 -phosphate (a central intermediate in the de novo synthesis of purine nucleotides) and its a-anomer have been synthesized from 2,3,5-tri-0-benzoyl-aj8-D-arabinofuranosyl azide, 3,5-0-isopropylidene-aj8-D-xylofuranosylamine, and ethyl 5-amino-l-a- and - -d-ribofuranosylimidazole-4-carboxylates, respectively. The jS-anomers of (493)— 

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The purine and pyrimidine ring compounds found in nucleic acids are known as "bases," even though some of them have almost no basic character. Nucleosides are the N-glycosyl derivatives of the bases with ribose or 2-deoxyribose. Tire nucleotides are phosphate esters of nucleosides. Similar names are applied to related compounds such as adenosine triphosphate (ATP) that are not present in DNA or RNA. The names of the principal nucleotides from which the nucleic acids are formed are given in Table 5-1. The... 

A related method, of preparative value, was subsequently developed.323 It makes use of the 2-hydroxypyridyl esters (74), of nucleoside 5 -phosphates, which can readily be obtained from nucleoside 5 -phosphates and 2-pyridinol. The reaction of the derivative (74) with glycosyl phosphates in anhydrous pyridine gives rise to the... 

On the other hand, as seen in this chapter and in earlier chapters, the formation of phosphates of adenine (e.g., AMP, ADP, and ATP), guanidine (e.g., GTP), cytosine (e.g.,cytidine monophosphate [CMP]), uracil (e.g., uridine monophosphate [UMP]), and dTMP have all involved the carbohydrate scaffold as a building block for the formation of the finished heterocyclic base (purine or pyrimidine). It is also important to realize that, as part of nucleotide salvage pathways, it has been found that a family of enzymes collectively known as phosphorylases serves to catalyze reactions between free bases and phosphate esters of carbohydrates (and related compounds). For example, as shown in Scheme 14.13, the generalized enzyme, purine nucleoside phosphorylase (EC 2.4.2.1), catalyzes the conversion of a purine with... 

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