- The Reaction of 2′-Deoxynucleosides with N-(2-Chloro1,1,2-trifluoroethyl)diethylamine: Mechanisms of O2,3′-Anhydro-2′-deoxynucleoside and By-product Formation
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Reaction mechanisms consistent with the formation of isopropylidene-like trans-furanose-3′,5′-[2-(R)(S)-aminochlorofluoromethyl-1,3-dioxanyl] -2′-deoxynucleoside intermediates 6, O2,3′-anhydro-2′-deoxynucleosides 7 and other minor reaction products and the yield-limiting effect of 6 on the cyclization of 7 are proposed.
- Sehgal, Raj K.,Turcotte, Joseph G.
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- A Novel One-step Procedure for the Conversion of Thymidine into 2,3'-Anhydrothymidine
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2,3'-Anhydrothymidine (3) is obtained in ca. 65percent yield by heating thymidine (2) with an excess of diphenyl sulphite in dimethylacetamide solution; (3) reacts with lithium azide to give 3'-azido-3'-deoxythymidine in good yield.
- Rao, T. Sudhakar,Reese, Colin B.
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Read Online
- Radiosynthesis of [18F]-labelled pro-nucleotides (ProtIDes)
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Phosphoramidate pro-nucleotides (ProTides) have revolutionized the field of anti-viral and anti-cancer nucleoside therapy, overcoming the major limitations of nucleoside therapies and achieving clinical and commercial success. Despite the translation of P
- Cavaliere, Alessandra,Probst, Katrin C.,Paisey, Stephen J.,Marshall, Christopher,Dheere, Abdul K.H.,Aigbirhio, Franklin,McGuigan, Christopher,Westwell, Andrew D.
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- Antiviral activity of 2,3′-anhydro and related pyrimidine nucleosides against hepatitis B virus
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Various 2,3′-anhydro analogs of 5-substituted 1-(2-deoxy-β-d- lyxofuranosyl)uracils (10-15) and a related 1-(3-O-mesyl-2-deoxy-β-d- lyxofuranosyl) pyrimidine nucleoside analog (18) have been synthesized for evaluation as a new class of potential anti-HBV
- Srivastav, Naveen C.,Mak, Michelle,Agrawal, Babita,Tyrrell, D. Lorne J.,Kumar, Rakesh
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scheme or table
p. 6790 - 6793
(2011/01/04)
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- Synthesis, structure, and biological evaluation of C-2 sulfonamido pyrimidine nucleosides
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The C-2 sulfonamido pyrimidine nucleosides were prepared by opening the 2,2′- or 2,3′-bond in anhydronucleosides under nucleophilic attack of sulfonamide anions. Reaction of the sodium salt of p-toluenesulfonamide or 2-(aminosulfonyl)-N,N-dimethylnicotinamide with 2,2′-anhydro-1-(β-D-arabinofuranosyl)cytosine gave the C-2 sulfonamido derivatives in excellent yields. Ring opening of the less reactive 2,2′-anhydrouridine and 2,3′-anhydrothymidine could be accomplished with DBU/CH3CN activation of p-toluenesulfonamide, giving moderate yields for C-2 sulfonamido derivatives. The action of acetic acid or ZnBr2/CH2Cl2 on 5-methyl-N2-tosyl-1-(2-deoxy-5-O-trityl-β-D-threo- pentofuranosyl)isocytosine led to the cleavage of both the protection group and the nucleoside bond, yielding 5-methyl-N2-tosylisocytosine as the major product. Structures of the prepared C-2 sulfonamido nucleosides were confirmed by the 1D and 2D NMR experiments, and X-ray structural analysis of 4-imino-N2-tosylamino-1-(β-D-arabinofuranosyl)pyrimidine. Both methods confirmed β-configuration and anti-conformation of the 2-sulfonamido nucleosides. The investigated compounds displayed moderate inhibition of tumor cell growth in vitro, as determined by the MTT assay using six different human tumor cell lines.
- Krizmani?, Irena,Vi?njevac, Aleksandar,Lui?, Marija,Glava?-Obrovac, Ljubica,?ini?, Mladen,?ini?, Biserka
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p. 4047 - 4057
(2007/10/03)
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- An improved synthesis of azidothymidine
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A convenient and high yielding procedure is described for a direct conversion of thymidine (1) into 2,3'-anhydrothymidine (2) using the Mitsunobu reaction. Isolation and characterization of two new compounds, 3 and 4, are discussed. AZT has been synthesized from 1 in two steps, in 62% overall yield, by heating 2 with NaN3 in DMF.
- Balagopala, Meher I.,Ollapally, Abraham P.,Lee, Henry J.
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p. 899 - 906
(2007/10/03)
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- Synthesis of 2,3'-anhydro-2'-deoxyuridines and 2,3'-didehydro-2',3'-dideoxyuridines using polymer supported fluoride
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Reaction of methyl 5-O-tert-butyldiphenylsilyl-2-deoxy-3-O-p-toluenesulfonyl-α,β-D-eryt hro-pentofuranoside (2) with silylated uracils 3 using trimethylsilyl trifluoromethanesulfonate (TMS triflate) as catalyst afforded after crystallization in Et2O the corresponding β-nucleosides 4. Reaction of 4 with tetrabutylammonium fluoride (TBAF) or Amberlyst A-26 resin (F--form) in THF at room temperature or at reflux gave the corresponding deprotected 2,3'-anhydro-2'-deoxyuridines 6 and 2',3'-didehydro-2',3'-dideoxyuridines 7, respectively.
- Larsen,Kofoed,Pedersen
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p. 1121 - 1125
(2007/10/02)
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- Action of nucleophiles on 2,3'-anhydrothymidine: Side-reactions involving the possible intermediacy of 2,5'-anhydro-1-(2-deoxy-β-D-threo-pentofuranosyl)thymine
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2,3'-Anhydrothymidine (1) reacts with the sodium salt of propane-2-thiol and with sodium phenyl selenide to give 5'-substituted products [(3b) and (3c), respectively] in addition to the expected 3'-substituted 2',3'-dideoxynucleoside derivatives [(2b) and
- Joshi,Reese
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p. 2371 - 2374
(2007/10/02)
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- Conversion of Some Pyrimidine 2'-Deoxyribonucleosides into the Corresponding 2',3'-Didehydro-2',3'-dideoxynucleosides
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Thymidine 4b was converted into 2,3'-anhydro-1-(2'-deoxy-β-D-threo-pentofuranosyl)thymine 7b in ca. 65percent isolated yield by being heated at 155 deg C with an excess of diphenyl sulfite and 1-methylimidazole in N,N-dimethylacetamide solution. 2'-Deoxyuridine 4a, 2'-deoxy-5-ethyluridine 4c and 2'-deoxy-5-fluorouridine 4d were similarly converted into 2,3'-anhydronucleosides which were isolated as their 5'-O-(tert-butyldimethylsilyl) derivatives 8a, 8c and 8d in 51, 50 and 59percent yield, respectively.When the oxetane derivatives 5a-d, prepared by the literature procedure from the parent 2'-deoxynucleosides 4a-d, were heated with an excess of sodium hydride in N,N-dimethylacetamide solution at 100 deg C, they were converted into the corresponding 2',3'-didehydro-2',3'-dideoxynucleosides 6a-d in 68, 76, 69 and 74percent isolated yield, respectively.The latter compounds were similarly prepared from the 2,3'-anhydronucleosides 7a-d in 71, 81, 69 and 74percent isolated yield, respectively. 2,3'-Anhydro-5'-O-(tert-butyldimethylsilyl)-2'-deoxy-5-(trifluoromethyl)- and -5-iodo-1-(β-D-threo-pentofuranosyl)uracil 8e and 8f, which were themselves prepared from the parent 2'-deoxynucleosides 4e and 4f, respectively, in ca. 60 and 50percent yield, were converted by a three-step procedure via the intermediate 2'-deoxy-3'-(phenylseleno) derivatives 10e and 10f into the corresponding 2',3'-didehydro-2',3'-dideoxynucleosides 6e and 6f in 52 and 49percent overall yield, respectively.Compound 8e was also converted into 2',3'-dideoxy-5-(trifluoromethyl)uridine 11b and 3'-azido-2',3'-dideoxy-5-(trifluoromethyl)uridine 11c in 49 and 66percent overall yield, respectively.
- Joshi, Bhalchandra V.,Rao, T. Sudhakar,Reese, Colin B.
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p. 2537 - 2544
(2007/10/02)
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- New synthetic 'tricks'. Trimethylsilyl triflate mediated cleavage of hindered silyl ethers
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An alternative, mild procedure for the cleavage of t-butyldimethylsilyl and triphenylsilyl ethers to alcohols is shown, which is based on an exchange reaction with trimethylsilyl triflate below 0°C. t-Butyldiphenylsilyl groups are not removed under these
- Bou,Vilarrasa
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p. 567 - 568
(2007/10/02)
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