Synthesis nucleoside

Purine, 2,6-dithioxo-1,2,3,6-tetrahydro-dethiation, 5, 558 Purine, 8-ethoxy-synthesis, 5, 577, 596 Purine, 6-ethoxycarbonylmethyl-nucleoside synthesis, 5, 561 Purine, 8-ethoxy-7-methyl-synthesis, 5, 577 Purine, 9-ethyl-synthesis, 5, 593 Purine, 6-fonnyl-reactions, 5, 547 synthesis, 5, 593 Purine, 8-fonnyl-reactions, 5, 547 Purine, 2-fluoro-synthesis, 5, 597 Purine, 6-fluoro-alkylation, 5, 529 synthesis, 5, 563, 573 Purine, 6-fluoro-9-methyl-reactions, with ammonia, 5, 562 Purine, 6-furfurylamino- — see Kinetin Purine, 9-glycofuranosyl-synthesis, 5, 572 Purine, 2-glycosyl-synthesis, 5, 587 Purine, 8-glycosyl-synthesis, 5, 585 Purine, 9-glycosyl-synthesis, 5, 572 Purine, 8-halo-synthesis, 5, 598 Purine, 2-hydrazino-synthesis, 5, 593 Purine, 8-o -hydroxyethyl-synthesis, 5, 574... 

Pyrido[3,4-d]pyrimidine-2,4-dione synthesis, 3, 215 Pyridopyrimidines, 3, 201 iV-alkylations, 3, 206 biological activity, 3, 260-261 1-electron reductions, 3, 207 IR spectra, 3, 204 mass spectra, 3, 204 MO calculations, 3, 204 NMR, 3, 202, 203 nucleophilic substitution, 3, 213 8-nucleosides synthesis, 3, 206 physical properties, 3, 201-205 protonation, 3, 206 radical reactions, 3, 215 reactions with water, 3, 207 reduced... 

HILBERT JOHNSON Nucleoside Synthesis Nucleoside synthesis front brontosugars and methoxypyiimidines (see Vorbrueggen). 

The 3-phenylpropionate ester has been used in nucleoside synthesis. It is cleaved by a-chymotrypsin (37°, 8-16 h, 70-90% yield). It can be cleaved in the presence of an acetate. ... 

When the Dnseoc group is used in nucleoside synthesis, the coupling yields are determined by measuring the absorbance at 350 nm of each eluate from the Dnseoc-deprotection steps containing the 5-(dimethylamino)naphthalene-l-yl-vinyl sulfone or by measuring the fluorescence at 530 nm. ... 

The use of this group in nucleotide and nucleoside synthesis has been reviewed. ... 

Wang J, Jin Y, Rapp KL, Schinazi RF, Chu CK (2007) D- and L-2, 3 -didehydro-2, 3 -dideoxy-3 -fluoro-carbocyclic nucleosides synthesis, anti-HIV activity and mechanism of resistance. J Med Chem 50 1828-1839... 

The mono-silylated or free acetamides, which are liberated during silylation with 22 a, can, furthermore, interfere with any subsequent reaction, e.g. with electrophiles. Thus in the one-pot/one-step silylation, Friedel-Crafts catalyzed, nucleoside synthesis starting from protected sugar derivatives and pyrimidine or purine bases, the mono- or bis-silylated amides such as 22 a can compete with less reactive silylated heterocycHc bases for the intermediate electrophilic sugar cation to form protected 1-acetylamino sugars in up to 49% yield [42, 47]. On silylation with trimethylsilylated urea 23 a the Hberated free urea is nearly insoluble in most solvents, for example CH2CI2, and thus rapidly precipitated [43]. 

H. VoRBRUGGEN, C. RuH-PoHLENZ, Organic Reactions, Vol 55, 2000, Wiley, New York [59a] H. VoRBRUGGEN, C. Ruh-Pohlenz, Handbook of Nucleoside Synthesis, ). Wiley ... 

For further Pummerer reactions with silylated heterocyclic bases see Refs. 414a—414i in Handbook of Nucleoside Synthesis , H. Vorbruggen, C. Ruh-Pohlenz, Wiley-Inter-science. New York, 2001... 

Saito Y, Hanawa K, Kawasaki N et al (2006) Acridone-labeled base-discriminating fluorescence (BDF) nucleoside synthesis and their photophysical properties. Chem Lett... 

The problems in the nucleoside synthesis arise in the linkage of the 3-N atoms of the pyrimidines and the 9-N atoms of the purines with the l -C atom of ribose, not only without enzyme control, but also under conditions extant on the primordial Earth. How might such reactions occur There have naturally been many attempts... 

Although the results of all experiments so far carried out on nucleoside synthesis under prebiotic conditions have been disappointing, the next step, to give the nucleotides, has been carried out using nucleosides synthesized in today s laboratories. There are two preconditions for nucleotide syntheses ... 

Scheme 8.7. Nucleoside synthesis, glycoside synthesis, and aromatic alkylation with a dielectrophilic donor.

In an early example, Mukaiyama and coworkers used hetaryl onium salts for nucleoside synthesis. The active hetaryl onium salt is generated in situ from the reaction of 2-chloro-3-ethylbenzoxazolium tetrafluoroborate 77 and the glycosyl acceptor. With benzimidazole as glycosyl acceptor, the resulting 2-(l-benzimida-zoyl)benzoxazolium tetrafluoroborate 78 was obtained. The reaction between the hetaryl onium salt 78 and hemiacetal donor 1 occurs at 60 °C to activate the hemiacetal and thereby reveal the glycosyl acceptor. This procedure led to the formation of nucleoside 80 with exclusive 1,2-trans selectivity [139]. The nucleoside 81 was similarly prepared. Alternatively, 2-fluoro-l-methylpyridinium tosylate 79 directly... 

Krenitsky, T.A., Koszalka, G.W. and Tuttle, J.V., Purine nucleoside synthesis, an efficient method employing nucleoside phosphorylases. Biochemistry, 1981, 20, 3615-3621. 

A reaction which is analogous to the orthoester synthesis but which utilises glycosyl oxazolines affords means of synthesising, 2-trans-2 amino-2-deoxy-glycoside derivatives. Treatment of the gluco compomd (17) with phenol in the presence of toluene- -sulphonic acid thus gave the glycoside (18), and it was also utilised in a nucleoside synthesis 48). 

We were first attracted to chiral pyrrolidines by the possibility of applying methods used in C-nucleoside synthesis (1) to the synthesis of the antiprotozoal antibiotic anisomycin (p from D-ribose (2). 

Nitro compounds, synthesis of, 12, 3 Nitrone-olefin cycloadditions, 36, 1 Nitrosation, 2, 6 7, 6 Nucleosides, synthesis of, 55, 1... 

The Tsuji-Trost reaction, more commonly applied to carbocyclic nucleoside synthesis, has been used in the synthesis of famciclovir 21 (Scheme 5) <2000T4589>. Reaction of 2-amino-6-chloropurine with allylic carbonate 22 in the presence of Pd2DBA3 and bis(diphenylphosphino)ethane (DPPE) gave a 1 1 ratio of 23 to 24 after 1 h (DBA = dibenzylideneacetone). However, a ratio of >95 5 in favor of the thermodynamically favored N-9 isomer 23 was subsequently obtained upon further stirring, highlighting the reversibility of the reaction in this specific instance. 

Few examples of this class of compound have been reported, although the cyclic sulfate 158 and the cyclic sulfite 159 have been reported as intermediates in carbohydrate and nucleoside synthesis, repectively <1996JOC480, 2001J(P1)1855>. 

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