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1.
We describe concise and efficient synthesis of 2′-deoxyadenosine-3′-O-triphosphate (2′-d-3′-ATP) and 2′-deoxycytidine-3′-O-triphosphate (2′-d-3′-CTP) which are well known for their various biological applications. One-pot synthetic methodology was used to convert N6-Benzoyl-5′-O-levulinoyl-2′-deoxyadenosine into N6-Benzoyl-5′-O-levulinoyl-2′-deoxyadenosine-3′-O-triphosphate in 72% yield. One-step concurrent deprotection of N6-Benzoyl and 5′-O-levulinoyl groups using concentrated aqueous ammonia resulted in 2′-d-3′-ATP in 75% yield. The same synthetic strategy was successfully employed to convert N4-Benzoyl-5′-O-levulinoyl-2′-deoxycytidine into 2′-d-3′-CTP in 66% yield.  相似文献   

2.
In an effort to develop an efficient synthetic method of highly diastereoselective (2′R)- and (2′S)-2′-deoxy[2′-2H]guanosines, chemoenzymatic conversion was investigated. The synthesis of (2′R > 98% de)-2′-deoxy[2′-2H]guanosine was achieved by biological transdeoxyribosylation using (2′R > 98% de)-2′-deoxy[2′-2H]uridine, 2,6-diaminopurine, and Enterobacter aerogenes AJ-11125, followed by treatment with adenosine deaminase. (2′S > 98% de)-2′-Deoxy[2′-2H]guanosine was synthesized from (2′S > 98% de)-2′-deoxy[2′-2H]uridine and 2,6-diaminopurine using thymidine phosphorylase and purine nucleoside phosphorylase instead of E. aerogenes AJ-11125.  相似文献   

3.
l-Ascorbic and d-isoascorbic acids were employed in syntheses of 9-(2′,3′,4′-trihydroxybutyl)adenines protected at 3′ and 4′ oxygens (all four enantiomers) and at 2′ oxygen (2′S,3′R and 2′S,3′S enantiomers).  相似文献   

4.
Two triprenylated toluquinone and toluhydroquinone marine fungal metabolites, 5-methyl-2-[(2′E,6′E)-3′,7′,11′-trimethyl-2′,6′,10′-dodecatrienyl]-2,5-cyclohexadiene-1,4-dione and 5-methyl-2-[(2′E,6′E)-3,7,11-trimethyl-2′,6′,10′-dodecatrienyl]-1,4-benzenediol, were synthesized in four and five steps, respectively, from 2-methyl-1,4-benzoquinone. The synthesis extends the applicability of the oxidative ether cleavage of hydroquinone dimethyl ethers with argentic oxide under acidic conditions to include the oxidative demethylation of polyprenylated-1,4-dimethoxy-toluhydroquinones with a quantitative survival of the oxidation- and acid-sensitive polyprenyl side chain.  相似文献   

5.
A new pyrrolidinyl peptide nucleic acid (PNA) comprising of an alternate sequence of 4′-nucleobase-modified proline with (2′R,4′S) configuration and a (1S,2S)-2-aminocyclopentanecarboxylic acid [(2′R,4′S)-acpcPNA] backbone was synthesized and its DNA-, RNA- and self-pairing properties studied. Tm and CD studies suggested that the (2′R,4′S)-acpcPNA forms antiparallel hybrids to DNA and RNA with high sequence and direction specificity. The stability of these hybrids is comparable to those of the (2′R,4′R)-acpcPNA hybrids previously reported by our group. On the other hand, experiments with a self-complementary sequence indicated that the new (2′R,4′S)-acpcPNA forms a more stable antiparallel self-hybrid than (2′R,4′R)-acpcPNA.  相似文献   

6.
Different acid anhydrides (of C2 to C7 aliphatic fatty acids and benzoic acid) have been used to study the selective acylation of primary/secondary hydroxyl groups in 2-phenyl-4-(d-threo-1′,2′,3′-trihydroxypropyl)-2H-1,2,3-triazole, 2-phenyl-4-(d-erythro-1′,2′,3′-trihydroxypropyl)-2H-1,2,3-triazole, 2-phenyl-4-(d-arabino-1′,2′,3′,4′-tetrahydroxybutyl)-2H-1,2,3-triazole and 2-phenyl-4-(d-lyxo-1′,2′,3′,4′-tetrahydroxybutyl)-2H-1,2,3-triazole in the presence of Candida antarctica lipase B in diisopropyl ether. Among the different acid anhydrides, butanoic anhydride was found to be the most efficient acylating agent (for butanoylation); for acetylation, vinyl acetate gave the best results. The reactions with both these acylating agents were highly selective and efficient yielding exclusively the monoacylated products in 95-99% yields in 1-5 h.  相似文献   

7.
A regioselective Suzuki-Miyaura cross-coupling reaction on 3′,5′-dibromo pyridinium N-(2′-azinyl)aminides is reported. A series of 3′-aryl(or heteroaryl)-5′-bromo-pyridinium N-(2′-pirazinyl)aminides were obtained in good yields. Two isomeric 3′,5′-diaryl pyridinium N-(2′-azinyl)aminides were also prepared.  相似文献   

8.
We designed a novel 2′-O,5′-N bridged nucleic acid, 2′,5′-BNAON, whose sugar puckering was fixed to S-type conformation by an N-O linkage. A dimer unit formed from 2′,5′-BNAON-U and thymidine was synthesized via a coupling reaction between a protected 2′,5′-BNAON-U monomer and a thymidine derivative. Introduction of 2′,5′-BNAON-U into DNA was carried out using conventional phosphoramidite chemistry with a DNA synthesizer. The hybridization abilities of 2′,5′-BNAON-U-modified oligonucleotides against DNA or RNA complement were evaluated.  相似文献   

9.
The reaction of oxides of internal trans- and cis-perfluoroolefins with (1S, 4S)- or racemic camphor thiosemicarbazone leads to the formation of trans- and cis-isomers of (1S, 4S)- or racemic camphor 5′-fluoro-4′-hydroxy-4′,5′-di(perfluoroalkyl)-1′,3′-thiazolinyl-2′-hydrazones, respectively. Unsymmetrical dodecafluoro-2,3-epoxyhexane yields a mixture of regioisomeric hydrazones. The molecular structure of the trans-isomer of (1S, 4S)-camphor 5′-fluoro-4′-hydroxy-4′,5′-bis(trifluoromethyl)-1′,3′-thiazolinyl-2′-hydrazone has been established by X-ray crystallography. The quite rare example of cocrystallization of two diastereomers of the latter in homochiral crystal (sp. group P21) has been revealed.  相似文献   

10.
A one-pot synthesis of the hitherto unreported pyrido[5″,6″:4,5;3″2″:4′,5′]dithieno[3,2-d:3′,2′-d′]dipyrimidine-4,8(3H,9H)-dione 6a-o and pyrazino[5″,6″:4,5;3″2″:4′,5′]dithieno[3,2-d:3′,2′-d′]dipyrimidine-4,8(3H,9H)-dione 6p-y pentaheterocyclic systems, based on the tandem aza-Wittig heterocumulene-mediated annulation strategy is described.  相似文献   

11.
Pedro Traar 《Tetrahedron letters》2006,47(30):5293-5296
The synthesis of (R)-2′,3′-dihydroxypropyl 5-deoxy-5-dimethylarsinoyl-β-d-riboside, (S)-2′-hydroxy-3′-sulfonylpropyl 5-deoxy-5-dimethylarsinoyl-β-d-riboside and (S)-2′-hydroxy-3′-sulfooxypropyl 5-deoxy-5-dimethylarsinoyl-β-d-riboside, common naturally-occurring arsenicals in algae and molluscs, is reported.  相似文献   

12.
Acid-catalyzed reaction of benzotriazole, 5,6-dimethylbenzotriazole and 5,6-dichlorobenzotriazole with di-O-acetyl-d-xylal in ethyl acetate afforded 1-(4′-O-acetyl-2′,3′-dideoxy-d-glycero-pent-2′-enopyranosyl)benzotriazole derivatives and small amounts of 1,2,3-trideoxy-4-O-acetyl-3-(benzotriazolyl)-d-threo-pent-1-enopyranose derivatives. The reactions using di-O-acetyl-l-arabinal led to the formation of the corresponding 1- and 2-(3′,4′-di-O-acetyl-2′-deoxy-l-erythro-pentopyranosyl)benzotriazole derivatives. In addition the enantiomers of the above 2′, 3′-unsaturated N-glycosyl compounds were also obtained. The configurations and conformations of the products obtained were determined by NMR spectroscopy.  相似文献   

13.
Jason L. Ormsby 《Tetrahedron》2008,64(50):11370-11378
Rearrangements readily occur in Scholl oxidations and interfere with the construction of certain molecular architectures. 3,3?,4,4′,4″,4?,5′,5″-Octamethoxy-1,1′,2′,1″,2″,1?-quaterphenyl and 3,3?,4,4′,4′′,4?,5′,5′-octamethyl-1,1′,2′,1″,2″,1?-quaterphenyl, which were conceived as precursors to benzenoid strips, rearranged under Scholl conditions to the unexpected C2v-substituted products 1,2,5,6,9,10,12,13-octamethoxydibenzo[fg,op]naphthacene and 1,2,5,6,9,10,12,13-octamethyldibenzo[fg,op]naphthacene. This corrects a widely propagated error in the literature in which the assignments of 1,2,5,6,9,10,12,13-octamethoxydibenzo[fg,op]naphthacene (C2v) and 1,2,5,6,8,9,12,13-octamethoxydibenzo[fg,op] naphthacene (C2h) are crossed. A mechanism involving the migration of an aryl ring on an arenium cation intermediate is proposed.  相似文献   

14.
Philip Børsting 《Tetrahedron》2006,62(6):1139-1149
Four different nucleosides with olefinic 2′-modifications were prepared; 2′-C-methylene, 2′-C-(propen-1-yl), 2′-C-allyl and 2′-O-allyl uridines, respectively. These were incorporated into dinucleotides with allyl phosphate or vinyl phosphonate linkages. Hence, six different dinucleotides were studied as substrates for RCM reactions, and from four of these, cyclic dinucleotides with connections between 2′-C and phosphorus of 3-6 atoms were obtained.  相似文献   

15.
A novel bridged nucleic acid analogue, 2′-deoxy-trans-3′,4′-BNA thymine monomer, was successfully synthesized. An ab initio calculation and X-ray structure analysis revealed that the trans-fused bicyclo[5.3.0]decane structure of the 2′-deoxy-trans-3′,4′-BNA effectively constrained the sugar puckering in C2-endo with appropriate γ, δ and χ angles.  相似文献   

16.
The n-(ethynyl)quinolines were satisfactorily prepared by heterocoupling reaction between the appropriate n-chloroquinoline and 2-methyl-3-butyn-2-ol, catalyzed by palladium, followed by treatment with a catalytic amount of powdered sodium hydroxide in toluene. The n-(ethynyl)quinolines were transformed in the corresponding conjugate 1,4-bis[n′-(quinolyl)]buta-1,3-diynes by oxidative dimerization, catalyzed by cuprous chloride, with excellent yields. Moreover, the heterocoupling between n′-haloquinoline and n′-(ethynyl)quinoline (n′, 2′ or 3′), catalyzed by palladium, gives 2′,2′-bis(quinoline) or 1,2-di(3′-quinolyl)ethyne, respectively. The same coupling reaction with zerovalent nickel complexes, gives a mixture of 1,2,4- and 1,3,5-tri(n′-quinolyl)benzene.  相似文献   

17.
Lipase-catalyzed asymmetric acetylation of a mixture of (6R,1′S,4′S,5′R)- and (6R,1′R,4′R,5′S)-7′-norsesquisabinen-4′-ol (3) afforded a separable mixture of the recovered former and the acetate of the latter. The recovered alcohol was oxidized to (6R,1′S,5′R)-sesquisabina ketone (2), whose absolute configuration could be assigned by its CD comparison with (1R,5S)-sabina ketone (4). Conversion of (6R,1′S,5′R)-sesquisabina ketone (2) to the bioactive pheromone revealed the stereostructure of the male aggregation pheromone of the stink bug Erysarcoris lewisi (Distant) to be (2Z,6R,1′S,5′S)-2-methyl-6-(4′-methylenebicyclo[3.1.0]hexyl)hept-2-en-1-ol (sesquisabinen-1-ol, 1).  相似文献   

18.
Cascade assembly of N,N′-dialkylbarbituric acids and aldehydes in the presence of bromine leads to the selective and efficient formation of substituted 1,5-dihydro-2H,2′H-spiro(furo[2,3-d]pyrimidine-6,5′-pyrimidine)-2,2′,4,4′,6′-(1′H,3H,3′H)-pentones in 70-88% yields via a complex cascade process. Spirobarbiturates containing the furo[2,3-d]pyrimidine framework are a class of compounds with interesting pharmacological and physiological activity.  相似文献   

19.
The lipophile extract of Lonchocarpusnicou roots afforded the new pyranochalcone 3-O-methylabyssinone A as well as the new rotenoids 7′-hydroxytephrosin, and 7′-nor-6′-oxo-2′,3′-dehydrorotenone, both compounds occurring with the known 7′-hydroxydeguelin and 7′-nor-6′-oxo-2′,3′-dehydro-12aβ-hydroxyrotenone. Furthermore, two rotenoid epoxides previously reported as resulting from the direct oxidative conversion of rotenone and 12aβ-hydroxyrotenone, respectively, were isolated for the first time from a plant source. All the structures were established on the basis of UV, MS, and NMR data.  相似文献   

20.
Synthesis of a novel 1′,2′-oxetane-uridine bearing a 2′-C-methyl substituent, [1-(1′,3′-O-anhydro-3′-C-methyl-β-d-psicofuranosyl)uracil], is described. Key to its construction was the use of 6-O-(p-toluoyl)-1,2:3,4-di-O-isopropylidene-3-C-methyl-d-psicofuranose as a nucleosidation substrate, which itself was derived from d-fructose. Anti-HCV activity was examined for the corresponding triphosphate which was not found to be an inhibitor of HCV NS5B 1b wild type polymerase in vitro. The 1′,2′-oxetane uridine triphosphate without 2′-C-methyl substitution was similarly inactive, however, the guanosine analog displayed modest inhibition (IC50 = 10 μM).  相似文献   

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