59090-41-4

Upstream product

• 3056-12-0 2-deoxy-3,5-di-O-(p-toluoyl)-α-D-erythropentofuranosyl chloride 
• 61135-33-9 2'-deoxy-5-ethynyluridine 
• 6214-65-9 5-acetyluracil 
• 951-78-0 2'-deoxyuridine 

Relevant academic research and scientific papers

Ethynyl side chain hydration during synthesis and workup of "clickable" oligonucleotides: Bypassing acetyl group formation by triisopropylsilyl protection

Clickable oligonucleotides with ethynyl residues in the 5-position of pyrimidines (ethdC and ethdU) or the 7-position of 7-deazaguanine (ethc7Gd) are hydrated during solid-phase oligonucleotide synthesis and workup conditions. The side products were identified as acetyl derivatives by MALDI-TOF mass spectra of oligonucleotides and by detection of modified nucleosides after enzymatic phosphodiester hydrolysis. Ethynyl → acetyl group conversion was also studied on ethynylated nucleosides under acidic and basic conditions. It could be shown that side chain conversion depends on the nucleobase structure. Triisopropylsilyl residues were introduced to protect ethynyl residues from hydration. Pure, acetyl group free oligonucleotides were isolated after desilylation in all cases.

SYNTHESIS OF 2-DEOXY-β-D-RIBONUCLEOSIDES AND2,3-DIDEOXY.β-D-PENTOFURANOSIDES ON IMMOBILIZED BACTERIAL CELLS

Alginate gel-entrapped cells of auxotrophic thymine-dependent strain of E. coli catalyze the transfer of 2-deoxy-D-ribofuranosyl moiety of 2'-deoxyuridine to purine and pyrimidine bases as well as their aza and deaza analogs.All experiments invariably gave β-anomers; in most cases, the reaction was regiospecific, affording N9-isomers in the purine and N1-isomers in the pyrimidine series.Also a 2,3-dideoxynucleoside can serve as donor of the glycosyl moiety.The acceptor activity of purine bases depends only little on substitution, the only condition being the presence of N7-nitrogen atom.On the other hand, in the pyrimidine series the activity is limited to only a narrow choice of mostly short 5-alkyl and 5-halogeno uracil derivatives.Heterocyclic bases containing amino groups are deaminated; this can be avoided by conversion of the base to the corresponding N-dimethylaminomethylene derivative which is then ammonolyzed.The method was verified by isolation of 9-(2-deoxy-β-D-ribofuranosyl) derivatives of adenine, guanine, 2-chloroadenine, 6-methylpurine, 8-azaadenine, 8-azaguanine, 1-deazaadenine, 3-deazaadenine, 1-(2-deoxy-β-D-ribofuranosyl) derivatives of 5-ethyluracil, 5-fluorouracil, and 9-(2,3-deoxy-β-D-pentofuranosyl)hypoxanthine, 9-(2,3-deoxy-β-D-pentofuranosyl)-6-methylpurine, and other nucleosides.

THE SYNTHESIS AND CRYSTAL STRUCTURE OF 5-ACETYL-2'-DEOXYURIDINE

5-Acetyl-2'-deoxyuridine (1) has been synthesised by treating 2'-deoxy-5-ethynyluridine with dilute sulphuric acid.Condensation of the trimethylsilyl derivate of 5-acetyluracil with 2-deox-3,5-di-O-p-toluoyl-α-D-erythropentofuranosyl chloride gave a mixture of α- and β-anomeric blocked nucleosides from which the α-anomer was isolated and the p-toluoyl groups removed to give 5-acetyl-1-(α-D-2-deoxyerythropentofuranosyl)uracil.Only a poor yield of the β-anomer (1) was obtained by this procedure.The UV spectra and m.p. obtained for 1 differed from the values quoted in the literature.The crystals of 1 are monoclinic, space group P21, with a=9.525, b=12.16, c=5.22 Angstroem, β=92.03 deg and two molecules in the unit cell.The structure was refined by least-squares calculations to R 3.4percent for 1426 observed counter amplitudes.The pyrimidine ring is essentially planar with the acetyl group inclined at 6 deg to it.The sugar ring has the highly unusuael C(4')-exo conformation and the arrangement about C(4')-C(5') is such that O(5') is oriented gauche with respect to both O(1') and C(3').The glycosidic torsion angle O(1')-C(1')-N(1)-C(6) is 56 deg (anti conformation).