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1.
An efficient strategy for the synthesis of (2′-5′)adenylate trimer conjugates with 2′-terminal 3′-O-(ω-hydroxyalkyl) and 3′-O-(ω-carboxyalkyl) spacers is reported. Npeoc-protected adenosine building blocks 37--40 for phosphoramidite chemistry carrying a 3′-O-[11-(levulinoyloxy)undecyl], 3′-O-{2-[2-(levulinoyloxy)ethoxy]ethyl}, 3′-O-[5-(2-cyanoethoxycarbonyl)pentyl], and 3′-O-{5-[(9H-fluoren-9-ylmethoxy)carbonyl]pentyl} moiety, respectively, were prepared (npeoc = 2-(4-nitrophenyl)ethoxycarbonyl). Condensation with the cordycepin (3′-deoxyadenosine) dimer 1 led to the corresponding trimers 42, 43, 47 , and 48. Whereas the levulinoyl (lev) and 9H-fluoren-9-ylmethyl (fm) blocking groups could be cleaved off selectively from the trimers 42, 43 , and 48 yielding the intermediates 44, 45 , and 49 for the synthesis of the 3′-O-(ω-hydroxyalkyl)trimers 53, 54 and the cholesterol conjugates 59--61 , the 2-cyanoethyl (ce) protecting group of 47 , however, could not be removed in a similar manner from the carboxy function. Trimer 47 served as precursor for the preparation of the trimer 55 with a terminal 3′-O-(5-carboxypentyl)adenosine moiety. The metabolically stable 3′-O-alkyl-(2′--5′)A derivatives were tested regarding inhibition of HIV-1 syncytia formation and HIV-1 RT activity. Only the conjugate 59 showed significant effects, whereas the trimers 53--55 and the conjugates 60 and 61 were less potent inhibitors, even at 100-fold larger concentrations.  相似文献   

2.
In the title compound, C20H16N2O5, both of the 1‐acetyl­isatin (1‐acetyl‐1H‐indole‐2,3‐dione) moieties are planar and form a dihedral angle of 74.1 (1)°. Weak intermolecular hydrogen bonds and C—H?π interactions stabilize the packing in the crystal.  相似文献   

3.
A series of new 2′–5′ oligonucleotides carrying the 9-(3′-azido-3′deoxy-β-D-xylofuranosyl)adenine moiety as a building block has been synthesized via the phosphotriester method. The use of the 2-(4-nitrophenyl)ethyl (npe) and 2-(4-nitrophenyl)ethoxycarbonyl (npeoc) blocking groups for phosphate, amino, and hydroxy protection guaranteed straightforward syntheses in high yields and easy deblocking lo form the 2′–5′ trimers 21 , 22 , and 25 and the tetramer 23 . Catalytic reduction of the azido groups in [9-(3′-azido-3′-deoxy-β-D-xylofuranosyl)adenine]2′-yl-[2′-(Op-ammonio)→ 5′]-[9-(3′-azido-3′-deoxy-β-D-xylofuranosyl)adenin]-2′-yl-[2′-(Op-ammonio)→ 5′]-9-(3′-azido-3′-deoxy-β-D-xylofuranosyl)adenine ( 21 ) led to the corresponding 9-(3′-amino-3′-deoxy-β-D-xylofuranosyl)-adenine 2′–5′ trimer 26 in which the two internucleotidic linkages are formally neutralized by intramolecular betaine formation.  相似文献   

4.
A series of new 2′-O-methylribonucleoside 3′-O-[2-(4-nitrophenyl)ethyl dialkylphosphoramidites] 27 – 31 , 33 – 38 , 40 – 44 , and 45 – 50 were synthesized and their stability and reactivity compared in automated oligonucleotide synthesis with the standard 2′-O-methylribonucleoside 3′-O-(β-cyanoethyl diisopropylphosphoramidites) 32 , 39 , 45 , and 51 , respectively. The 2-(4-nitrophenyl)ethyl (npe) and 2-(4-nitrophenyl)ethoxycarbonyl (npeoc) groups were used for the protection of the base moieties.  相似文献   

5.
Conformational analysis using 1H n.m.r. data (δ, 3J and NOE) has been carried out on several derivatives of 2′,3′,-O-isopropylideneadenosine bearing various substituents at positions C-5′, C-8 and N-6. Conformational modifications are assigned to specific interactions between the sugar and purine moieties and also to solvent effects.  相似文献   

6.
An efficient synthesis of (3′‐terminally) 3′(2′)‐O‐aminoacylated pCpA derivatives is described, which could lead to the production of (aminoacyl)‐tRNAs following T4 RNA ligase mediated ligation. The tetrahydrofuranyl (thf) group was used as a permanent protective group for the 2′‐OH of the cytidine moiety which can be removed during the purification of the 3′(2′)‐O‐aminoacylated‐pCpA. This approach allowed for a general synthesis of (3′‐terminally) 3′(2′)‐O‐aminoacylated oligonucleotides. The fully protected pCpA 14 was synthesized by phosphoramidite chemistry and treated with NH3 solution to remove the 2‐cyanoethyl and benzoyl groups (→ 15 ; Schemes 1 and 2). The 2′‐O‐thf‐protected‐pCpA 15 was coupled with α‐amino acid cyanomethyl esters, and the products 20a – c were deprotected and purified with AcOH buffer to afford 3′(2′)‐O‐aminoacylated pCpA 21a – c in high yields. The 3′(2′)‐O‐aminoacylated pCpA were efficiently ligated with tRNA(? CA) to yield (aminoacyl)‐tRNA which was an active substrate for the ribosome.  相似文献   

7.
The stereospecific cis-hydroxylation of 1-(2,3-dideoxy-β-D -glyceropent-2-enofuranosyl)thymine (1) into 1-β-D -ribofuranosylthymine (2) by osmium tetroxide is described. Treatment of 2′,3′-O, O-isopropylidene-5-methyl-2,5′-anhydrouridine (8) with hydrogen sulfide or methanolic ammonia afforded 5′-deoxy-2′,3′-O, O-isopropylidene-5′-mercapto-5-methyluridine (9) and 2′,3′-O, O-isopropylidene-5-methyl-isocytidine (10) , respectively. The action of ethanolic potassium hydroxide on 5′-deoxy-5′-iodo-2′,3′-O, O-isopropylidene-5-methyluridine (7) gave rise to the corresponding 1-(5-deoxy-β-D -erythropent-4-enofuranosyl)5-methyluracil (13) and 2-O-ethyl-5-methyluridine (14) . The hydrogenation of 2 and its 2′,3′-O, O-isopropylidene derivative 4 over 5% Rh/Al2O3 as catalyst generated diastereoisomers of the corresponding 5-methyl-5,6-dihydrouridine ( 17 and 18 ).  相似文献   

8.
Use of the Wittig reaction for the synthesis of derivatives of bromoenosuloses and bromoenuronic esters Treatment of 3-O-benzyl (or 3-O-methyl)-1, 2-O-isopropylidene-α-D -xylo-pentodialdo-1, 4-furanoses ( 2 or 1 ) with acetylbromomethylidenetriphenylphosphorane ( 3 ), benzoylbromomethylidenetriphenylphosphorane ( 4 ) or bromoethoxycarbonylmethylidenetriphenylphosphorane ( 5 ) gave in good to excellent yields the expected enose ( 6--11 ). In all cases but one ( 8 where some 10% of the E-isomer was formed) the reaction led to the exclusive formation of the Z-isomer whose configuration was established by NMR.  相似文献   

9.
In the title compounds, C12H12N2O2, (I), and C17H14N2O2, (II), respectively, the indole rings are planar and the vinyl groups lie out of the indole planes, making dihedral angles of 33.48 (5) and 41.31 (8)°, respectively. In (II), the dihedral angle between the phenyl and indole ring planes is 32.06 (6)°. In both mol­ecules, the double bond connecting the methyl­nitro­vinyl group and the indole nucleus adopts an E configuration. Notwithstanding the differences in space group [C2/c for (I) and P212121 for (II)], the mode of packing of compounds (I) and (II) is determined by similar inter­molecular N—H⋯O hydrogen‐bonding inter­actions, forming chains that run parallel to [101] in (I) and [001] in (II).  相似文献   

10.
Intramolecular cyclisation of properly protected and activated derivatives of 2′,3′-secouridine ( = 1-{2-hydroxy-1-[2-hydroxy-1-(hydroxymethyl)ethoxy]-ethyl}uracil; 1 ) provided access to the 2,2′-, 2,3′-, 2,5′-, 2′,5′-, 3′,5′-, and 2′,3′-anhydro-2′,3′-secouridines 5, 16, 17, 26, 28 , and 31 , respectively (Schemes 1–3). Reaction of 2′,5′-anhydro-3′-O-(methylsulfonyl)- ( 25 ) and 2′,3′-anhydro-5′-O-(methylsulfonyl)-2′,3′-secouridine ( 32 ) with CH2CI2 in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene generated the N(3)-methylene-bridged bis-uridine structure 37 and 36 , respectively (Scheme 3). Novel chiral 18-crown-6 ethers 40 and 44 , containing a hydroxymethyl and a uracil-1-yl or adenin-9-yl as the pendant groups in a 1,3-cis relationship, were synthesized from 5′-O-(triphenylmethyl)-2′,3′-secouridine ( 2 ) and 5′-O,N6-bis(triphenylmethyl)-2′,3′-secoadenosine ( 41 ) on reaction with 3,6,9-trioxaundecane-1,11-diyl bis(4-toluenesulfonate) and detritylation of the thus obtained (triphenylmethoxy) methylcompound 39 and 43 , respectively (Scheme 4).  相似文献   

11.
The 5′-amino-5′-deoxy-2′,3′-O-isopropylideneadenosine ( 4 ) was obtained in pure form from 2′,3′-O-isopropylideneadenosine ( 1 ), without isolation of intermediates 2 and 3 . The 2-(4-nitrophenyl)ethoxycarbonyl group was used for protection of the NH2 functions of 4 (→7) . The selective introduction of the palmitoyl (= hexadecanoyl) group into the 5′-N-position of 4 was achieved by its treatment with palmitoyl chloride in MeCN in the presence of Et3N (→ 5 ). The 3′-O-silyl derivatives 11 and 14 were isolated by column chromatography after treatment of the 2′,3′-O-deprotected compounds 8 and 9 , respectively, with (tert-butyl)dimethylsilyl chloride and 1H-imidazole in pyridine. The corresponding phosphoramidites 16 and 17 were synthesized from nucleosides 11 and 14 , respectively, and (cyanoethoxy)bis(diisopropylamino)phosphane in CH2Cl2. The trimeric (2′–5′)-linked adenylates 25 and 26 having the 5′-amino-5′-deoxyadenosine and 5′-deoxy-5′-(palmitoylamino)adenosine residue, respectively, at the 5′-end were prepared by the phosphoramidite method. Similarly, the corresponding 5′-amino derivatives 27 and 28 carrying the 9-[(2-hydroxyethoxy)methyl]adenine residue at the 2′-terminus, were obtained. The newly synthesized compounds were characterized by physical means. The synthesized trimers 25–28 were 3-, 15-, 25-, and 34-fold, respectively, more stable towards phosphodiesterase from Crotalus durissus than the trimer (2′–5′)ApApA.  相似文献   

12.
The 2′-deoxyribofuranose analog of the naturally occurring antibiotics SF-2140 and neosidomycin were prepared by the direct glycosylation of the sodium salts of the appropriate indole derivatives, with 1-chloro-2- deoxy-3,5-di-O-p-toluoyl-α-D-erythropentofuranose ( 5 ). Thus, treatment of the sodium salt of 4-methoxy-1H- indol-3-ylacetonitrile ( 4a ) with 5 provided the blocked nucleoside, 4-methoxy-1-(2-deoxy-3,5-di-O-p-toluoyl-β- D-erythropentofuranosyl)-1H-indol-3-ylacetonitrile ( 6a ), which was treated with sodium methoxide to yield the SF-2140 analog, 4-methoxy-1-(2-deoxy-β-D-erythropentofuranosyl)-1H-indol-3- ylacetonitrile ( 7a ). The neosidomycin analog ( 8 ) was prepared by treatment of the sodium salt of 1H-indol-3-ylacetonitrile ( 4b ) with 5 to obtain the blocked intermediate 1-(2-deoxy-3,5-di-O-p-toluoyl-β-D-erythropentofuranosyl) ?1H-indol-3-ylace-tonitrile ( 6b ) followed by sodium methoxide treatment to give 1-(2-deoxy-β-D-erythropentofuranosyl)-1H- indol-3-ylacetonitrile ( 7b ) and finally conversion of the nitrile function of 7b to provide 1-(2-deoxy-β-D- erythropentofuranosyl)-1H-indol-3-ylacetamide ( 8 ). In a similar manner, indole ( 9a ) and several other substituted indoles including 1H-indole-4-carbonitrile ( 9b ), 4-nitro-1H-indole ( 9c ), 4-chloro-1H-indole-2-carboxamide ( 9d ) and 4-chloro-1H-indole-2-carbonitrile ( 9e ) were each glycosylated and deprotected to provide 1-(2-deoxy-β-D-erythropentofuranosyl)-1H-indole ( 11a ), 1-(2-deoxy-β-D-erythropentofuranosyl)-1H-indole-4- carbonitrile ( 11b ), 4-nitro-1-(2-deoxy-β-D-erythropentofuranosyl)-1H-indole ( 11c ), 4-chloro-1-(2-deoxy-β-D- erythropentofuranosyl)-1H-indole-2-carboxamide ( 11d ) and 4-chloro-1-(2-deoxy-β-D-erythropentofuranosyl)- 1H-indole-2-carbonitrile ( 11e ), respectively. The 2′-deoxyadenosine analog in the indole ring system was prepared for the first time by reduction of the nitro group of 11c using palladium on carbon thus providing 4-amino-1-(2-deoxy-β-D-erythropentofuranosyl)- 1H-indole ( 16 , 1,3,7-trideaza-2′-deoxyadenosine).  相似文献   

13.
2′–5′ Adenylate trimers 41–44 carrying the (tert-butyl)dimethylsilyl (tbds) group at the 3′-OH position of various sugar moieties were synthesized via the phosphoramidite method. The use of the (tert-butyloxy)carbonyl (boc) and 2-(4-nitrophenyl)ethylsulfonyl (npes) groups for 2′-OH protection in neighbourhood to the 3′-O-tbds residue was compared during the synthesis of the target trimers. For other functional positions, the use of the 2-(4-nitrophenyl)ethyl (npe) and 2-(4-nitrophenyl)ethoxycarbonyl (npeoc) blocking groups were favoured.  相似文献   

14.
The title copper complex, [Cu(H2P2O7)(C15H11N3)]2·4.5H2O, consists of two very similar independent Cu(Tpy)H2P2O7 monomeric units (Tpy is 2,2′:6′,2′′‐terpyridine) plus four and a half water molecules of hydration, some of which are disordered. Tpy units bind through the usual triple bite via their N atoms, and the H2P2O72− anions coordinate through two O atoms from two different phosphate units. Each independent CuN3O2 chromophore can be described as a slightly deformed square pyramid, with one of them having a sixth, semicoordinated, O atom from a centrosymmetrically related CuN3O2 unit in a weakly bound second apical position suggesting an octahedral environment for the cation and weak dimerization of the molecule. The two independent complex molecules are connected via two strong O—H...O interactions between the phosphate groups to form hydrogen‐bonded dinuclear units, further linked into [111] columns, resulting in a very complex three‐dimensional supramolecular structure through a variety of classical and nonclassical hydrogen bonds, as well as π–π interactions.  相似文献   

15.
Two new one‐dimensional CuII coordination polymers (CPs) containing the C2h‐symmetric terphenyl‐based dicarboxylate linker 1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylate (3,3′‐TPDC), namely catena‐poly[[bis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ4O,O′:O′′:O′′′] monohydrate], {[Cu(C20H12O4)(C2H7N)2]·H2O}n, (I), and catena‐poly[[aquabis(dimethylamine‐κN)copper(II)]‐μ‐1,1′:4′,1′′‐terphenyl‐3,3′‐dicarboxylato‐κ2O3:O3′] monohydrate], {[Cu(C20H12O4)(C2H7N)2(H2O)]·H2O}n, (II), were both obtained from two different methods of preparation: one reaction was performed in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) as a potential pillar ligand and the other was carried out in the absence of the DABCO pillar. Both reactions afforded crystals of different colours, i.e. violet plates for (I) and blue needles for (II), both of which were analysed by X‐ray crystallography. The 3,3′‐TPDC bridging ligands coordinate the CuII ions in asymmetric chelating modes in (I) and in monodenate binding modes in (II), forming one‐dimensional chains in each case. Both coordination polymers contain two coordinated dimethylamine ligands in mutually trans positions, and there is an additional aqua ligand in (II). The solvent water molecules are involved in hydrogen bonds between the one‐dimensional coordination polymer chains, forming a two‐dimensional network in (I) and a three‐dimensional network in (II).  相似文献   

16.
Syntheses for 9-(β-D -ribofuranosyl)uric acid ( 16 ) and its 5′-monophosphate 14 have been achieved starting from guanosine and applying the 2-(p-nitrophenyl)ethyl group for protection of the aglycon moiety as well as the phosphate function. A more efficient and direct approach to 14 uses O6, O8-dibenzyl protection and phosphorylation by the Yoshikawa procedure. The various protected intermediates have been characterized by spectroscopic means and elemental analysis.  相似文献   

17.
The Zn complexes bis(acetylacetonato‐κ2O,O′)bis{4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine‐κN1}zinc(II), [Zn(C5H7O2)2(C22H17N3S)2], (I), and {μ‐4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine‐κ2N1:N1′′}bis[bis(acetylacetonato‐κ2O,O′)zinc(II)], [Zn2(C5H7O2)4(C22H17N3S)], (II), are discrete entities with different nuclearities. Compound (I) consists of two centrosymmetrically related monodentate 4′‐[4‐(methylsulfanyl)phenyl]‐4,2′:6′,4′′‐terpyridine (L1) ligands binding to one ZnII atom sitting on an inversion centre and two centrosymmetrically related chelating acetylacetonate (acac) groups which bind via carbonyl O‐atom donors, giving an N2O4 octahedral environment for ZnII. Compound (II), however, consists of a bis‐monodentate L1 ligand bridging two ZnII atoms from two different Zn(acac)2 fragments. Intra‐ and intermolecular interactions are weak, mainly of the C—H...π and π–π types, mediating similar layered structures. In contrast to related structures in the literature, sulfur‐mediated nonbonding interactions in (II) do not seem to have any significant influence on the supramolecular structure.  相似文献   

18.
5-(α-Fluorovinyl)tryptamines 4a, 4b and 5-(α-fluorovinyl)-3-(N-methyl-1′,2′,5′,6′-tetrahydropyridin-3′- and -4′-yl) indoles 5a, 5b were synthesized using 5-(α-fluorovinyl)indole ( 7 ). The target compounds are bioisosteres of 5-carboxyamido substituted tryptamines and their tetrahydropyridyl analogs.  相似文献   

19.
The reaction of 2,2′:6′,2′′‐terpyridine (terpy) with CuCl2 in the presence of sodium sulfite led to the synthesis of the ionic complex aquachlorido(2,2′:6′,2′′‐terpyridyl‐κ3N,N′,N′′)copper(II) chlorido(dithionato‐κO)(2,2′:6′,2′′‐terpyridyl‐κ3N,N′,N′′)cuprate(II) dihydrate, [CuCl(C15H11N3)(H2O)][CuCl(S2O6)(C15H11N3)]·2H2O, (I), and the in situ synthesis of the S2O62− dianion. Compound (I) is composed of a [CuCl(terpy)(H2O)]+ cation, a [Cu(S2O6)(terpy)] anion and two solvent water molecules. Thermogravimetric analysis indicated the loss of two water molecules at ca 363 K, and at 433 K the weight loss indicated a total loss of 2.5 water molecules. The crystal structure analysis of the resulting pale‐green dried crystals, μ‐dithionato‐κ2O:O′‐bis[chlorido(2,2′:6′,2′′‐terpyridyl‐κ3N,N′,N′′)copper(II)] monohydrate, [Cu2Cl2(S2O6)(C15H11N3)2]·H2O, (II), revealed a net loss of 1.5 water molecules and the formation of a binuclear complex with two [CuCl(terpy)]+ cations bridged by a dithionate dianion. The crystal‐to‐crystal transformation involved an effective reduction in the unit‐cell volume of ca 7.6%. In (I), the ions are linked by O—H...O hydrogen bonds involving the coordinated and solvent water molecules and O atoms of the dithionate unit, to form ribbon‐like polymer chains propagating in [100]. These chains are linked by Cu...Cl interactions [3.2626 (7) Å in the cation and 3.3492 (7) Å in the anion] centred about inversion centres, to form two‐dimensional networks lying in and parallel to (01). In (II), symmetry‐related molecules are linked by O—H...O hydrogen bonds involving the partially occupied disordered water molecule and an O atom of the bridging thiosulfite anion, to form ribbon‐like polymer chains propagating in [100]. These chains are also linked by Cu...Cl interactions [3.3765 (12) Å] centred about inversion centres to form similar two‐dimensional networks to (I) lying in and parallel to (02), crosslinked into three dimensions by C—H...O=S and C—H...O(water) interactions.  相似文献   

20.
An efficient route to 2′,3′‐dihydro‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives is described. It involves the reaction of isatine, 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ5‐phosphanylidene)ethan‐1‐one, and different amines in the presence of CS2 in dry MeOH at reflux (Scheme 1). The alkyl carbamodithioate, which results from the addition of the amine to CS2, is added to the α,β‐unsaturated ketone, resulting from the reaction between 1‐phenyl‐2‐(1,1,1‐triphenyl‐λ5‐phosphanylidene)ethan‐1‐one and isatine, to produce the 3′‐alkyl‐2′,3′‐dihydro‐4′‐phenyl‐2′‐thioxospiro[indole‐3,6′‐[1,3]thiazin]‐2(1H)‐one derivatives in excellent yields (Scheme 2). Their structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses.  相似文献   

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