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1.
In aqueous and aqueous-ethanolic buffer solutions at pH<9, 2, 2-bifuryl and 2, 2-furoin give two-electron polarographic electroreduction waves, the half-wave potentials of which depend on the pH. The primary product of the electroreduction of 2, 2-bifuryl is trans-1,2-dihydroxy-1,2-bis(, -furyl)ethylene, which then rearranges into 2, 2-furoin. The anode-cathode wave of 2,2-bifuryl has been studied by means of a Kalousek commutator. It has been shown that the polarographic behavior of 2,2-bifuryl and 2, 2-furoin is similar to that of benzil and benzoin, but differs from the behavior of analogs of the pyridine series.  相似文献   

2.
Two new glycosides, gomphotin (1) and gomphotoxin (13), and also the known gomphoside (9) have been isolated from the leaves ofGomophocarpus fruticosus. Compounds (1) and (9) contain a 4,6-dideoxyhexosulose residue as the sugar component, and (13) a 6-deoxyhexosulose, which are attached to glycolic OH groups of the aglycons by 3-O-1,2-O-2 (9, 13) and 3-O-1,4-O-2 (1) acetal-ketal bonds. The structures of the new compounds are represented by the names (3-O-1,4-O-2)-(2,3-dihydroxy-4, 6dideoxyhexulosido)-14-hydroxy-5-card-20(22)-enolide* (1) and (3-O-1,2-O-2)-(2,3,4-trihydroxy-6-deoxyhexulosido)-14-hydroxy-5-card-20(22)-enolide* (13).State Scientific Center for Drugs of the Ministry of Health and the National Academy of Sciences of the Ukraine, Kharkov, fax 441118. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 824–832, November–December, 1995. Original article submitted May 22, 1995.  相似文献   

3.
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.  相似文献   

4.
Summary ,-bis-(p-Benzylphenyl)xylene was synthesized for the first time and its UV and infrared spectra determined.  相似文献   

5.
N-Methyl (ethyl, benzoyl, trifluoroacetyl)-substituted 3-methyl-2-phenyl-5-(3-methyl-2-phenyl-3,4-dehydropiperidyl-6) pyridines and di(N-oxide) of the correspondingly substituted ,ß-dipyridyl were prepared. A method for synthesizing 2-phenyldinicotinic acid was developed. Cyclodehydration of this acid gave 4-azafluorenone-2-carboxylic acid. Transformations of this acid were carried out with respect to two functional groups.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 813–817, June, 1986.  相似文献   

6.
Summary The dynamic mechanical properties of nylon 66 films and fibers have been examined, as a function of annealing and drawing, with a Vibron viscoelastometer. It is found that the transition is little affected by annealing treatments, but increase in orientation causes the transition to move to a higher temperature. Experiments, with X-ray diffraction of samples at elevated temperatures, lead to the conclusion that the triclinic to hexagonal phase change does not contribute significantly to the transition. Samples cut parallel and perpendicular to the drawing direction of nylon 66 film, have been used to show that the curves of dynamic tensile modulus versus temperature, for the parallel and perpendicular directions, cross in the neighborhood of the transition. This observation is discussed in relation to the suggestion that the transition is the glass transition in nylon 66.
Zusammenfassung Die dynamisch-mechanischen Eigenschaften von Filmen und Fasern aus Nylon 66 wurden als Funktion der Temperung und Verstreckung mit einem Virbon-Viskoelastometer untersucht. Die -Umwandlung wird wenig durch die Temperung beeinflußt, aber erhöhte Orientierung läßt siezu höheren Temperaturen verlagern. Messungen der Röntgenstreuung bei erhöhten Temperaturen führen zu dem Schluß, daß der Übergang triklin/hexagonal nicht wesentlich zu der -Umwandlung beiträgt. Proben aus verstrecktem Nylon-66-Film, parallel und senkrecht zur Streckrichtung geschnitten, zeigen, daß die Kurven des dynamischenE-Moduls gegen die Temperatur für beide Orientierungen sich in der Nachbarschaft der -Umwandlung überkreuzen. Diese Beobachtung wird hinsichtlich der Vermutung diskutiert, daß die -Umwandlung den Glasübergang in Nylon 66 darstellt.


With 5 figures and 2 tables  相似文献   

7.
Conclusion The reaction of 20,20-dimethoxy-16,17-epoxypregn-5-ene-3,21-diol-20-one with pyridine thiocyanate in the presence of carbethoxyhydrazine proceeds by two competing paths: cisopening of the oxide ring by a -SCN ion at the C17 atom, and substitution of one of the methoxyl groups by -NCS ion. As a result 2,20-dicarbethoxyhydrazones of pregn-5-ene-3,21-diol-20-one-[17,16-d]-1,3-oxathiolan-2-one and 20-methoxy-16,17-epoxypregn-5-ene-3-ol-[20,21-d]-1,3-oxazolidine-2-thione are formed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 911–914, April, 1987.  相似文献   

8.
Summary 1. The synthesis of the following neutral plasmalogens has been effected: -O-(octadec-1-enyl)-, distearoylglycerol, -O-(octadec-1-enyl)-, -dipalmitoylglycerol, -O-(hexadec-1-enyl)-, -distearoylglycerol, and -O-(pentadec-1-enyl)-, -dipalmitoylglycerol.2. During the synthesis, the following compounds were isolated and characterized by their physicochemical constants: the -octadec-1-enyl ether of glycerol, -(2-hydroxyoctadecyl) , -isopropylideneglyceryl ether, the tosylate of -(2-hydroxyoctadecyl) , -isopropylideneglyceryl ether, and -O-(2-tosyloxyoctadecyl) glycerol.3. The IR spectra of the -octadec-1-enyl ether of glycerol and the neutral plasmalogens have been studied.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 6, pp. 367–371, 1966  相似文献   

9.
Conclusions We have synthesized 1,2-O-(1-cyanoethylidene)-3,6,2, 3,4-penta-O-acetyl-6-O-trityl-4-O--D-glucopyranosyl--D-glucopyranose, which is a potential monomer for polycondensation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2571–2573, November, 1977.  相似文献   

10.
On electrolysis mono- and bicyclic furfuryl-substituted alcohols undergo intramolecular alkoxylation, giving polycyclic spirans. Spiro[perhydrobenzofuran-2, 2-(5-methoxy, 5H)furan] and spiro[4H, 5H, 6H, 11H-naphtho-(,)-furan-2(3H)] [2-(5-methoxy, 5H)furan], hitherto not described, are prepared in this way. On catalytic hydrogenation they give the previously unknown spiro[perhydrobenzofuran-2, 2-tetrahydrofuran] and spiro[4H, 5H, 6H, 11H-naphtho-(,)-furan-2(3H)][2-tetrahydrofuran].For Part XXIX see [1].  相似文献   

11.
The methyl ester of a new hydroxy acid of the piperidine series (-phenyl--(1,2, 5-trimethyl-4-hydroxy 4-piperidyl)acetic acid) has been prepared. Ethyl -(1,2, 5-trimethyl-4-hydroxy-4-piperidyl)acetate has been converted into the substituted pyridine, 1,1-diphenyl-2-(2-5-dimethyl-4-pyridyl)ethylene.  相似文献   

12.
Zusammenfassung Neue Oxathiaferrocenophane wurden durch Umsetzung von 1,1-Bis(hydroxymethyl)ferrocen mit Dithiolen dargestellt, welche Sauerstoff in den Alkylketten enthalten. Die Reaktion von 1,1-Bis(-hydroxyethyl)ferrocenen mit Dithiolen führte zu Mischungen von Diastereomeren, aus welchen reine Stereoisomere isoliert und charakterisiert wurden. Einige Aspekte des stereochemischen Verlaufes dieser Reaktionen werden diskutiert.
Diastereomere oxathia[n](1,1)ferrocenophane
Novel oxathiaferrocenophanes have been synthesized by the reaction of 1,1-bis(hydroxymethyl)ferrocene with dithiols bearing oxygen in chains. The reactions of 1,1-bis(-hydroxyethyl)ferrocenes with dithiols afforded mixtures of diastereomeric products from which pure stereoisomers were isolated and characterized. Some aspects concerning a stereochemical course of the reactions described are discussed.
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13.
In order to explain some discrepancies between the theoretical predictions and the experimental data for the thermodynamic properties of substitutional B 2 phases,Chang's theoretical model is extended by including the influence of second-nearest neighbor interactions. For this purpose a new parameter is introduced which is defined as the ratio of the interchange energies between second-nearest and first-nearest neighbors. Theoretical equations are derived for the compositional dependence of the activity and the partial molar enthalpy. Using literature data, the following phases are re-evaluated in terms of the disorder parameter and the newly introduced parameter : -AuZn, -AuCd, -AgMg, and -NiZn. Very good agreement is found between the theoretical curves and the experimental data for the four systems. The values of obtained range from 0.0 for -NiZn to 0.5 for -AuZn. The inclusion of second-nearest neighbor interactions has little influence on the values of . It is shown that the behavior of the activity curve in -AuZn can be explained in a physically more meaningful way by including interactions between all second-nearest neighbors rather than interactions between gold substitutional defects only, as was done byLibowitz.With 5 Figures  相似文献   

14.
Summary 1. The synthesis of L-(+)--oleoyl--linoleoyl--glycerylphosphorylethanolamine has been effected.2. During the investigations the following substances were isolated and characterized: L--oleoyl--glycerylphosphoryl-N-phthaloylethanolamine and L---linoleoyl--glycerylphosphoryl-N-phthanoylethanolamine.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 2, pp. 80–83, 1966  相似文献   

15.
Summary The synthesis of the following 1, 4-diphosphoinositides has been effected: the - (, -distearoyl) glyceryl ester of myoinositol 1, 4-diphosphate (VI) or (VII) and 1, 4-bis-[ - (, -distearoyl) glycerylphosphoryl] myoinositol (VIII).Khimiya Prirodnykh Soedinenii, Vol. 2, No. 4, pp. 230–233, 1966  相似文献   

16.
Condensation of 5- or 6-nitroindoline with L-arabinose gave 1--L-arabinopyranosyl-5 (or 6)-nitroindolines, which, after acetylation, dehydrogenation, and removal of the protective groups, are converted to 1--L-arabinopyranosyl-5(or 6)-nitroindoles and then to the corresponding amino derivatives. 1--L-Arabinopyranosyl-6-nitro-3-bromo-(iodo)indoles were obtained. The selective 2-O- and 3-O-deacetylation of 1-(2, 3, 4-tri-O-acetyl)--L-arabinopyranosyl-6-nitroindole was accomplished.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 224–229, February, 1979.  相似文献   

17.
Summary Several new N-acyl derivatives of 1-(4-hydroxy-2,3-dihydrobenzofuran-5-yl)-7,8-di methoxy-1,9 b,2,3,3 a,4-hexahydro-[1]benzopyrano[3,4-c]pyrazole-1-ene have been prepared by appropriate chemical transformation of isohydrazones of rotenone and amorphigenin. A study of their1H- and13C-NMR spectra confirmed the presence of the twocis 3a, 9b, 2 and 3a, 9b, 2 diastereomers in the parent isohydrazones and revealed the strong predominance of the conformers withendo orientation of the 3-NAc group. The conformations due to rotation about the 1,5-bond between rings C and D in the 4-OH and 4-O-substituted compounds were also determined by taking into account the anisotropic effect of aromatic rings A and D, and the hydrogen bond between 4-OH and the 2-N atom, as well as by inspecting the Dreiding models.
Darstellung und stereochemische Charakterisierung einiger N-Acyl-[1]benzopyrano[3,4-c]pyrazol-Derivate von Rotenoiden
Zusammenfassung Mittels geeigneter chemischer Transformationen von Isohydrazonen von Rotenon und Amorphigenin wurden einige neue N-Acyl-Derivate von 1-(4-Hydroxy-2,3-dihydrobenzofuran-5-yl)-7,8-dimethoxy-1,9 b,2,3,3 a,4-hexahydro-[1]benzopyrano[3,4-c]pyrazol-1-en hergestellt. Eine Untersuchung ihrer1H und13C-NMR-Spektren zeigt die Gegenwart von zweicis 3a, 9b, 2- und 3a, 9b, 2-Diastereomeren in den Ausgangs-Isohydrazonen und eine starke Bevorzugung der Konformeren mitendo-Orientierung der 3-NAc-Gruppe. Die Konformationen bezüglich der Rotation um die 1,5-Bindung zwischen Ring C und D werden für die 4-OH und 4-O-substituierten Verbindungen unter Berücksichtigung von Anisotropie-Effekten der aromatischen A- und D-Ringe, der Wasserstoffbrücken zwischen 4-OH und dem 2-N Atom und auch der Betrachtung der entspechenden Dreiding-Modelle diskutiert.
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18.
Conclusions On the basis of the rates of their acid hydrolysis, their optical activities, and their IR spectra, it has been established that the glycosides ofAesculus hippocastanum L. are (SK-1) 3--L-arabofuranosyloxy-5,7,4-trihydroxyflavone, (SK-2) 3--L-rhamnofuranosyloxy-5,7,4-trihydroxyflavone, (SK-3) 3--L-arabofuranosyloxy-5,7,3,4-tetrahydroxyflavone, and (SK-4) 3--L-rhamnofuranosyloxy-5,7,3,4-tetrahydroxyflavone.The glycoside SK-3 is identical with avicularin isolated from the leaves ofPsidium quajava [5]. The complete structures of the other three glycosides have been established for the first time.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 1, pp. 5–7, 1969  相似文献   

19.
Conclusions The reaction of 1,2-bis(methyldimethoxysilyl)ethane and the corresponding ethylene and acetylene derivatives with bis(2-hydroxyethyl)methylamine gives 1,2-bis(2,6-dimethyl-1,3-dioxa-6-aza-2-silacyclooctyl-2)ethane and the corresponding ethylene and acetylene derivatives. Analogously, 1,2-bis(vinyldimethoxysilyl)acetylene gave 1,2-bis(2-vinyl-6-methyl-1,3-dioxa-6-aza-2-silacyclooctyl-2)acetylene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1420–1421, June, 1988.  相似文献   

20.
The epoxide ring opening of 16,17-epoxy-17-ethynylandrost-4-en-3-one and its dicobalt hexacarbonyl complex on reacting with Py·HF, Py·HCl, and Py·HSCN was studied. The results of these reactions and the structure of the end products depend not only on the complexation of the acetylene bond, but also on the nucleophilic reagent used. On the basis of the reaction of a Co-coordinated 16,17-epoxy-17-ethynylandrost-4-en-3-one there has been developed a preparative method for the synthesis of pregn-4-ene-3,20-dione-[17,16-d]-1,3-oxazolidin-2-one.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2661–2666, November, 1992.  相似文献   

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