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1.
5,5′-Dialkyl-6,6′-dichloro-2,2′-bipyridines were synthesized starting from 3-substituted 2-chloro-6-iodopyridines using Pd-catalyzed coupling conditions. 6-Alkyl-3,5-dichloro-2H-1,4-oxazin-2-ones were excellent precursors for the synthesis of these functionalized 2-iodo-6-chloropyridines. 相似文献
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C. R. Noe H. -P. Buchstaller G. Haberhauer A. Holzner 《Monatshefte für Chemie / Chemical Monthly》1997,128(5):509-527
Zusammenfassung Die Synthese von geschützten 2,3-Dideoxy-2-hydroxymethyl-nucleosiden wird beschrieben. Die durch ein Mehrstufenverfahren aus Isopropylidenglycerol erhaltenen Nucleoside können als Bausteine zur Darstellung von Oligonucleotiden verwendet werden, deren 2- und 5-Positionen über eine Etherbrücke verbunden sind.
Synthesis of 2,3-dideoxy-2-hydroxymethyl nucleosides
Summary The synthesis of protected 2,3-dideoxy-2-hydroxymethyl nucleosides is presented. The nucleosides, obtained in a multi-step procedure starting from isopropylideneglycerol, may be used as building blocks for the synthesis of 2,5-ether linked oligonucleotides.相似文献
3.
Pavla Perlíková Neus Jornet Martínez Lenka Slavětínská Michal Hocek 《Tetrahedron》2012,68(39):8300-8310
A series of novel sugar-modified derivatives of cytostatic 6-hetaryl-7-deazapurine ribonucleosides (2′-deoxy-2′-fluororibo- and 2′-deoxy-2′,2-difluororibonucleosides) bearing an aryl or hetaryl group in position 6, was prepared and screened for biological activity. The fluororibo derivatives were prepared by aqueous palladium catalyzed cross-coupling reactions of the corresponding 6-chloro-7-deazapurine 2′-deoxy-2′-fluororibonucleoside 11 with (het)arylboronic acids. The key intermediate 11 was prepared by a six-step sequence from the corresponding arabinonucleoside by selective protection of 3′- and 5′-hydroxyls by acid-labile groups followed by stereoselective SN2 fluorination and deprotection. The difluororibo-series was prepared by non-stereoselective glycosidation of 6-chloro-7-deazapurine with benzoyl-protected 2-deoxy-2,2-difluoro-d-erythro-pentofuranosyl-1-mesylate followed by cross-couplings, separation of anomers and deprotection. The title nucleosides did not show considerable cytostatic or antiviral activity. 相似文献
4.
Tsutomu Tsuchiya Yoshiaki Takahashi Makoto Endo Sumio Umezawa Hamao Umezawa 《Journal of carbohydrate chemistry》2013,32(4):587-611
2′,3′-Dideoxy-2′-fluorokanamycin A (23) was prepared by condensation of 6-azido-4-0-benzoyl-2,3,6-trideoxy-2-fluoro-α-D-ribo-hexopyranosyl bromide (13) and a protected disaccharide (19). Methyl 4,6-0-benzylidene-3-deoxy-β-D-arabino-hexopyranoside (5) prepared from methyl 4,6-0-benzylidene-3-chloro-3-deoxy-β-D-allo-hexopyranoside (1) by oxidation with pyridinium chlorochromate followed by reduction with Na2 S2O4 was fluorinated with the DAST reagent to give methyl 4,6-O-benzylidene-2,3-dideoxy-2-fluoro-β-D-ribo-hexopyranoside (7). Successive treatment of 7 with NBS, NaN3 and SOBr2 gave 13. The structure of the final product (23) was determined by the 1H and 19F and shift-correlated 2D NMR spectra. 相似文献
5.
《Tetrahedron: Asymmetry》1998,9(12):2035-2042
A new synthetic procedure for the formation of 2-amino-2′-hydroxy-1,1′-binaphthyl, and a new purification procedure through the formation of Schiff bases, purification of the Schiff bases, and breakdown of the Schiff bases through amine exchange, are described. Through the new purification procedure, greater than 99% purity of the compound can be obtained easily and reliably. A set of procedures were examined to compare the efficiency and reliability to resolve 2-amino-2′-hydroxy-1,1′-binaphthyl into enantiomers. A new procedure was discovered to enrich enantiomeric excess from less than 10% to 95–99% in one step. Even a racemic mixture from an achiral procedure can be enriched to 67% e.e. in about 4% yield. The X-ray crystal structure of the racemic mixture [rhombohedral, space group Iba2, a=15.718(2) Å, b=21.703(2) Å, c=8.5398(9) Å, V=2913.2(5) Å3, R1=0.0705, Z=8, dcalcd=1.301 g/cm3, F(000)=1200 e] was solved to elucidate the intriguing behavior of this compound. 相似文献
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JianSONG XiaoLeiWANG YueJunXIANG ChungK.CHU RaymondSCHINAZI KangZHAO 《中国化学快报》2004,15(2):135-137
β-2′,3′-Dideoxy-2′-fluoro-3′-hydroxymethylarabinofuranosylthymine 10 and cytosine 12 were synthesized from L-xylose and were found to be inactive against HIV-1 in acutely infected lymphocytes. 相似文献
8.
A. A. Ilinova V. I. Bregadze A. N. Bogomazova I. A. Lobanova A. F. Mironov A. A. Semioshkin 《Russian Chemical Bulletin》2013,62(4):1115-1119
Conjugates of polyhedral boron hydrides with deoxyadenosine were synthesized by the opening of cyclic oxonium derivatives of closo-dodecaborate and cobalt bis(1,2-dicarbollide) with 2′-deoxyadenosine derivatives containing a nucleophilic group in the substituent at C(8). Biological studies of the derivatives obtained for cytotoxicity revealed that the derivatives based on closo-dodecaborate did not exhibit cytotoxicity. The conjugates obtained can be used in further biological trials as potential agents for boron neutron capture therapy of cancer. 相似文献
9.
The carbocyclic nucleoside 3-deazaaristeromycin has shown biological promise but a library of its derivatives upon which to expand this property is lacking. To address this situation, the synthesis of the two diastereomers of 2′-fluoro-3-deazaaristeromycin is described in a multistep convergent process that calls upon d-ribose for construction of the cyclopentyl fluoro units. 相似文献
10.
I. N. Merenkova E. A. Romanova N. I. Sokolova N. G. Dolinnaya T. S. Oretskaya Z. A. Shabarova 《Chemistry of Natural Compounds》1991,27(2):227-230
The synthesis of two 14-membered duplexes containing 2-fluoro-2-deoxyuridine and 1--D-arabinosyluracil, respectively., has been effected by chemical ligation (CL). During the synthesis of the first of them, it was observed that the ammonolysis of the completely blocked ACGGAU2F was accompanied by the transformation of the modified unit into arabinouridine with the formation of 45% of ACGGAUara. It has been established that the introduction of an electron-accepting substituent adjacent to the reacting 3-OH group has no influence on a characteristic feature established previously: CL is considerably more effective if the reacting phosphate group is present at the 3-end, and not the 5-end, of the oligonucleotide.M. V. Lomonosov Moscow State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 263–267, March–April, 1991. 相似文献
11.
The preparation of 6,6′-dibromo-2,2′-bipyridine and 6-bromo-2,2′-bipyridine are described. The dibromo compound was prepared by way of an improved cuprate synthesis resulting in a 72% yield. The monobromo species was prepared from the dibromo compound by way of metal-halogen exchange in 88% yield. 相似文献
12.
Values of the condensed phase standard (p = 0.1 MPa) molar enthalpy of formation for 2′- and 4′-methylacetophenones were derived from the standard molar energies of combustion, in oxygen, at T = 298.15 K, measured by static bomb combustion calorimetry. The values of the standard molar enthalpy of vaporization, at T = 298.15 K, were measured by Calvet microcalorimetry. Combining these two values, the following enthalpies of formation in the gas phase, at T = 298.15 K, were then derived: 2′-methylacetophenone, –(115.7 ± 2.4) kJ · mol−1, and 4′-methylacetophenone, –(122.6 ± 2.4) kJ · mol−1. Substituent effects are discussed in terms of stability and compared with other similar compounds. The value of the standard molar enthalpy of formation for 3′-methylacetophenone was estimated from isomerization schemes. 相似文献
13.
《Tetrahedron letters》1987,28(23):2623-2626
2′-5′,3′-5′ Linked triadenylates have been synthesized by direct bisadenylylation of adenosine 2′ and 3′ hydroxyls with an adenosine 5′-phosphorochloridite followed by oxidation. 相似文献
14.
Abstract The Williamson reaction between (R,S)-[1,1′-binaphthyl]-2, 2′-diol 1 and (R,S)-2,2′-bis (bromomethyl)-1,1′ binaphthyl 2 in acetone, gave the diastereoisomeric dioxacyclophanes (R?, S?)-3a and (R?, R?)-3b in high yield. 相似文献
15.
A convenient and high yield preparation of 4, 4′-dicarboxy-2, 2′-bipyridine from the oxidation 4, 4′-dimethyl-2, 2′-bipyridine with potassium dichromate in sulfuric acid is reported. 相似文献
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近年来发现用干扰素处理过的细胞胞浆提取物和双链RNA、ATP一起培养,可以生成一个低分子量的蛋白合成抑制剂,即5′-三磷酸-三聚2′,5′-腺苷酸(Ⅰ)。由于(Ⅰ)具有天然核酸中不存在的2′,5′-磷酸酯链以及它的抗病毒活性,因此引起不少化学家的兴趣,已有不少文章报导了(Ⅰ)及其类似物的合成,同时也发现不含三磷酸的三聚2′,5′-腺苷酸(Ⅱ)也同样具有活性。为了进一步研究(Ⅰ)的结构与活性关系,本文报导了用胞嘧啶碱基代替腺嘌呤碱基的(Ⅱ)的类似物C_(2′P5′)C_(2′P5′)A(Ⅲ)的合成。 相似文献
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A. V. Aksenov O. N. Nadein I. V. Borovlev Yu. I. Smushkevich 《Chemistry of Heterocyclic Compounds》1998,34(3):316-320
A method was developed for the synthesis of 2-alkyl(aryl)-1,2-dihydro-2,3-biquinolines, based on the addition of organolithium compounds to 2,3-biquinoline in the presence of tetramethylethylenediamine. Their oxidation with manganese dioxide led to 2-alkyl(aryl)-2,3-biquinolines.For Communication 2, see [1].Stavropol State University, Stavropol 355009, Russia. Russian Chemical-Technology University, Moscow 125190. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 350–354, March, 1998. 相似文献