Study of furan compounds

Research on synthesis of polycyclic spirans of the 1, 6-dioxaspiro-[4, 4]nonane group is continued. Electrolysis of methanol solutions of 2-furylcyclopentanol, 2-(5-methyl-furfuryl)cyclopentanol, and 2-furfuryl-1-indanol, gives, by intramolecular alkoxylation, spiro{perhydrocyclopenta[b]furan-2, 2-(5dihydrofuran)}, spiro{perhydrocyclopenta[b]furan-2, 2-(5-methoxy-5-methyl-2, 5-dihydrofuran)}, and spiro{2, 3, 3a, 8b-tetrahydro-4H-indeno[1, 2-b]furan-2, 2-(5-methoxy-2, 5-dihydrofuran)}, hitherto undescribed in the literature. Depending on the conditions, catalytic hydrogenation of these gives: spiro{perhydiocyclopenta[b]furan-2, 2-(5-methoxytetrahydrofuran)}, spiro{2, 3a, 8b-tetrahydro-4H-indeno[1, 2-b]furan-2, 2-(5-methoxytetrahydrofuran)}, spiro{perhydrocyclopenta[b]furan-2, 2-tetrahydrofuran}, and spiro{2, 3, 3a, 8b-tetrahydro-4H-indeno[1, 2-b]furan-2, 2-tetrahydrofuran}.For Part XXXI see [1].     

Heterylimidazoles IV. Homolytic dissociation of hexaaryldimidazolyls and their heterocyclic analogs

The rate constants and activation energies for homolytic dissociation of 2,2-di[ ()-naphthyl]-, 2,2-diquinolinyl-, and 2,2-di(9-acridinyl)-4,4,5,5-tetraphenyldiimidazolyls in toluene in the presence of,-diphenyl--picrylhydrazine were determined. The degrees of dissociation of the diimidazolyls were found. The effect of substituents on the stability of imidazolyl radicals is discussed.See [1] for communication III.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1536–1539, November, 1974.     

New chiral acyclic analogs of 2′-deoxynucleosides

Convenient methods for the synthesis of chiral 2,3-seco-2-deoxynucleosides were developed. An isopropylidene protective group was used to block the 3,5-hydroxy groups in 2,3-seco-uridine. Conversion of the hydroxymethyl group to a methyl group was accomplished by chlorination with a mixture of CCl₄ and Ph₃P with subsequent reduction with n-Bu₃SnH. 2,3-seco-2-Deoxyuridine was obtained after deacetonation. The (S) enantiomer was similarly synthesized starting from 1-(-D-arabinofuranosyl)uracil. 3-O-tert-Butyldimethylsilyl-5-O-(p-monomethoxytrityl)-2,3-seco-2-deoxyuridine, which has optically active centers at C₍₁₎ and C₍₄₎, was also synthesized.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 822–826, June, 1988.The authors thank Professor M. Ya. Karpeiskii for his constant interest in this research.     

Podand-porphyrins with peripheral chelates

Alkylation of 5-(3-nitro-4-hydroxyphenyl)-10,15,20-triphenylporphyrin with chloropyridines[2,6-dichloromethyl-and 2-chloromethyl-6-(2-nitrophenoxymethylpyridine)] as well as condensation by a mixed-aldehyde method starting with formylpyridines [2-(2-nitro-4-formylphenoxymethyl)-6-(2-nitrophenoxy-methyl-) or 2,6-di(2-nitro-4-formylphenoxymethyl)pyridine], benzaldehyde, and pyrrole are used to synthesize previously unknown podand-porphyrins containing from one to four peripheral chelates.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 475–481, April, 1991.     

Use of electrostatic interaction for chiral recognition. Enantioselective complexation of anionic binaphthyls with protonated amino-β-cyclodextrin

The studies using NMR and capillary zone electrophoresis clearly reveal that protonated 6^A-amino- 6^A-deoxy--cyclodextrin recognizes the chirality of anionic binaphthyl derivatives such as 1,1-binaphthyl-2,2-diyl phosphate and 1,1-binaphthyl-2,2-dicarboxylate through electrostatic interaction between the host and the guest and simultaneous inclusion.     

Reaction of Cytisine with 4″-Substituted Dibenzo-18-crown-6 Sulfonylchlorides

Sulfamides were synthesized via the reaction of cytisine with 4,4(5)-dibenzo-18-crown-6-disulfonyl-, 4-sec-butyl-4(5)-dibenzo-18-crown-6-sulfonyl-, and 4-acetyl-4(5)-dibenzo-18-crown-6-sulfonylchlorides. The structures of the prepared compounds were confirmed by PMR.     

Solubilization of lanthanide ions by cyclodextrins in basic aqueous solutions

Cyclodextrins form complexes with lanthanide ions in basic aqueous solutions. This complex formation in basic solution dramatically enhances the solubility of lanthanide ions, which are otherwise insoluble due to the formation of hydroxide gels. Solutions of the -cyclodextrin-Ce³⁺ complex effectively hydrolyze 2-deoxyadenosine-5-monophosphate to 2-deoxyadenosine.     

Vanadyl ion complexes with nucleotides

Summary Complexes of adenosine-5-triphosphate, adenosine-5-monophosphate, guanosine-5-monophosphate, inosine-5-monophosphate, cytidine-5-monophosphate and uridine-5-monophosphate with vanadyl ion, have been studied in the solid state by i.r. spectroscopy and magnetochemically. All complexes have normal magnetic moments, very close to the spin-only values. From the i.r. spectra it is suggested that the vanadyl ion is interacting with adenosine-5-triphosphate, through the N-1 of the purine ring, with adenosine-5-monophosphate, guanosine-5-monophosphate, inosine-5-monophosphate, through the N-7 of the purine ring, with cytidine-5-monophosphate through the N-3 of the pyrimidine ring, and most probably through the phosphate group with uridine-5-monophosphate. The complexes of vanadyl ion with the nucleotides are probably polymeric.     

Kinetic equations with a complex balanced stationary point

A class of ordinary differential equations including nonideal nonisothermal kinetics is introduced. The behavior of their solutions for the system with a positive complex-balanced stationary point is studied. Sufficient conditions for this point to exist are described.

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, . . .

     

Kinetics of oxidation of acrolein on a vanadium-molybdenum oxide catalyst

A kinetic study has shown that, in the range of low conversions, the reaction rate depends only on the partial pressure of oxygen. Comparison of the oxidation of acrolein and I-deuteroacrolein suggests that the splitting of the H–CO bond is not rate-limiting.

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, , , . 1- , H–CO .

     

Synthesis and structure of o-bis(2-fluoro-2,2-dinitroethyl)-nitromethyl ester of 2′-fluoro-2′, 2′-dinitroethyl-2″-fluoro-2″-nitroethylenecarboxime

Conclusions The product of conversion of O-bis(2-fluoro-2,2-dinitroethyl)nitromethylbis(2-fluoro-2,2-dinitroethyl)carboxime in methanol or ether is O-bis(2-fluoro-2,2-dinitroethyl)nitromethyl-2-fluoro-2,2-dinitroethyl-2'-fluoro-2-nitroethylenecarboxinie, the structure of which has been established by x-ray diffraction analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2019–2021, September, 1987.     

Propos sur l'interpretation de l'energie d'activation experimentale

Résumé Les résultats de divers travaux montrent que la valeurE _e de l'énergie activation expérimentale tirée des diagrammes d'Arrhénius varie avec la pression, dans le cas de réactions de décompositions endothermiques.L'analyse de divers modèles permet d'expliquer cette constatation en montrant que la grandeurE _e n'a pas le sens d'une énergie d'activation mais est une fonction de nombreux paramètres. Deux d'entre eux ont été retenus dans le cadre de cette étude: le terme d'écart à l'équilibre et le terme de gradient thermique, provoqué par l'endothermicité du phénomène.Cette analyse permet d'établir une prévision de la fonctionE _e (P) conforme aux résultats expérimentaux.

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The results from various investigations show that the experimental activation energy valueE _e derived from the Arrhenius diagrams varies with pressure for endothermic decomposition reactions.The analysis of various models allows this fact to be accounted for by showing thatE _e should be regarded not in its fundamental formulation, but as being a function of numerous parameters. Two of these were taken into account in the present study, i.e. deviation from equilibrium and a thermal gradient due to the fact that the phenomenon is endothermic.FunctionE _e (P) fitting the experimental results may be predicted by such an analysis.

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Zusammenfassung Die Ergebnisse verschiedener Untersuchungen zeigen, dass die aus den Arrhenius-Diagrammen abgeleiteten experimentellen Werte der AktivierungsenergieE _e bei endothermen Zersetzungsreaktionen mit dem Druck variieren.Die Analyse verschiedener Modelle ermöglicht eine Erklärung dieser Tatsache, indem gezeigt wird, dassE _e nicht in ihrer grundliegenden Formulierung betrachtet werden darf, sondern als Funktion einer Anzahl von Parametern. Zwei dieser Parameter wurden in der vorliegenden Untersuchung berücksichtigt d.h. die Abweichung von dem Gleichgewicht und der thermische Gradient, welcher infolge der endothermen Beschaffenheit der Erscheinung auftritt.Eine den Versuchsergebnissen entsprechende FunktionE _e (P) kann mittels einer solchen Analyse vorausgesagt werden.

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, _e, , . , _ee , . , : , , . _e (), , .

     

Two strong emitting coordination polymers with chain and ladder structures

Two coordination polymers [Zn(Cabo)₂(EtOH)₂(4,4-Bipy)] _n (1), and [Zn₂(Cabo)₂(NO₃)₂(4,4-Bipy)₂] _n (2) (Cabo = carbazolylacetate, 4,4-Bipy = 4,4-bipyridine) with chain and ladder structures, respectively, were prepared and characterized by X-ray single-crystal structural analysis. The results showed that the different anions of metal salts have a large effect on the construction of coordination frameworks. Both complexes show strong emissions in the solid state as well as high thermal stability.     

Reactions of pennogenin and related compounds. IV. Formation of (25R,22′R,25′R)-3β,3′β-diacetoxy-26,22′-epoxy-16,16′-bifurosta-5,20(22),5′,17′(20′)-tetraen-26′-ol from pennogenin diacetate under the action of BF3·Et2O

A new direction of the reaction of pennogenin diacetate with BF₃·Et₂O has been discovered in which a previously unknown dimeric steroid is formed — (25R,22R,25R)-3,3-diacetoxy-26,22-epoxy-16,16-bifurosta-5,20(22), 5,17(20)-tetraen-26-ol, the structure of which has been established as the result of an analysis of IR, UV,¹H and¹³C NMR, and mass spectra. A probable mechanism for the formation of the title compound from pennogenin diacetate is suggested.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok. Institute of Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 202–208, March–April, 1990.     

Synthesis of 9-diazo-4-azafluorenes

Stable diazo compounds of the azafluorene series, viz., 9-diazo-4-azafluorenone and 1,3-diphenyl-4-azafluorene, were obtained from 4-azafluorenone and 1,3-diphenyl-4-azafluorene tosylhydrazones. 1,2-Dicarbomethoxyspiro(4-azafluorene-9,3-cyclopropane) was obtained from 4-azafluorenone tosylhydrazone, and 4,5-dicarbomethoxyspiro(4-azafluorene-9,3-pyrazolenine) was obtained from 9-diazo-4-azafluorene. It is assumed that the product in the latter case is obtained as a result of reaction of a carbene, viz., 4-azafluorenylidene carbene, which is formed from 9-diazo-4-fluorene, with dimethyl acetylenedicarboxylate.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 951–953, July, 1979.     

1-Aryl-6-azauracile, 5. Mitt.: Die Synthese von 1-(β-Pyridyl)-6-azauracil-5-carbonsäure und einiger ihrer Derivate

Zusammenfassung Analog wie in vorherigen Mitteilungen^1–4 wurden -Pyridyl-hydrazono-cyanacetylcarbamidsäureäthylester (1), 1-(-Pyridyl)-5-cyan-6-azauracil (2), 1-(-Pyridyl)-6-azauracil-5-carbonsäure (3), deren Thioamid (4), und Amidoxim (5), welches in 1-(-Pyridyl)-5-[5-methyl-1,2,4-oxdiazolyl(3)]-6-azauracil (6) überge-führt wurde, hergestellt.

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-Pyridylhydrazono-cyanacetylcarbamic acid ethyl ester (1), l-(-pyridyl)-5-cyano-6-azauracil (2), 1-(-pyridyl)-6-azauracil-5-carboxylic acid (3), its thioamide (4) and amidoxime (5) were prepared as described in preceding communications. (5) was converted into l-(-pyridyl)-5-[5-methyl-1,2,4-oxdiazolyl(3)]-6-azauracil (6).

     

Simple and effective method for the synthesis of 3′,5′-substituted 1-β-D-arabinofuranosyluracil

3,5-Substituted arabinofuranosyluracil is a starting compound in 2-modifications. A convenient and effective method is proposed for the synthesis of 1-(3,5-di-o-trityl--D-arabinofuranosyl)uracil by successive reactions of 2,2-cyclization of uridine, 3,5-tritylation of the 2,2-anhydrouridine, and hydrolytic cleavage of the 2,2-anhydro bond.Institute of Organic Synthesis, Riga LV-1006. Odense Universitet, Kemisk Institut, Odense, Denmark. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 975–977, July, 1996. Original article submitted April 25, 1996.     

Infrared spectroscopic study of the adsoprtion of methacrylates on aerosil

The type and ratio of the attached groups was measured by FT-IR spectroscopy for the adsorption of three methacrylates. The adsorption enthalpies can be determined from a correlation with infrared frequency shifts.

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--. -.

     

Convenient synthesis of 5′-methyl-2′-desoxyuridines

A convenient method has been developed for the synthesis of 5-methyl-2-desoxyuridines. Chlorination of 5-O-benzoyl-5-methyluridines with a mixture of Ph₃P and CCl₄ in DMF affords the 2-desoxy-2-chloro-derivatives, which are then reduced with tributyltin hydride. The crystalline 5-O-benzoyl-5-methyl-2-desoxyuridines were obtained in overall yields of 40–60%. In a similar way, 5-O-benzoyluridine has given 5-O-benzoyl-2-desoxyuridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 246–248, February, 1989.     

Synthesis of 2,3,7,8-tetramethyldibenzofuran

3,4,3,4-Tetramethyldiphenyl ether readily forms 2,2-dihalo derivatives on bromination and iodination. Heating 2,2-diiodo-4,5,4,5-tetramethyldiphenyl ether with copper powder or oxidation, of 2,2-dilithio-4,5,4,5-tetramethyldiphenyl ether gives 2,3,7,8-tetramethyldibenzofuran, the structure of which was proved by alternative synthesis from 2,2-dinitroand 2,2-diamino-4,5,4,5-tetramethyldiphenyls.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1597–1599, December, 1972.