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  1. No Access

    Article

    Mass spectrometry and stereochemistry of heterocyclic compounds (review)

    The possibilities of the application of mass spectrometry for the determination of the orientation of substituents, the stereochemistry of ring fusion, and the configuration of an asymmetric heteroatom are exa...

    V. G. Zaikin, N. S. Vul'fson in Chemistry of Heterocyclic Compounds (1978)

  2. No Access

    Article

    Application of chromatographic mass spectrometry in the analysis of mixtures of the stereoisomers in the 1,2-dimethyl- and 1-ethyl-2-methyl-4-alkylperhydro-4-quinolol series

    It is shown on the basis of a comparison of the mass-spectral data obtained by admission of the individual substances into the ion source through direct introduction and by introduction of mixtures of the ster...

    V. G. Zaikin, V. I. Smetanin, N. S. Vul'fson… in Chemistry of Heterocyclic Compounds (1976)

  3. No Access

    Article

    Stereochemistry of 2, 7-disubstituted and 1,2,7-trisubstituted 4-alkyldecahydro-4-quinolols

    The configurations of the 2 and 4 centers in 1,2,7-trimethyl-, 2,7-dimethyl-, and 1,2-dimethyl-7-tert-butyl-4-alkyldecahydro-4-quinolols were assigned on the basis of a comparison of theI[M-CH3] +/I [M] + and I[m...

    V. G. Zaikin, A. A. Bakaev, N. S. Vul'fson… in Chemistry of Heterocyclic Compounds (1976)

  4. No Access

    Article

    Mass-spectrometric study of substituted 4-alkyldecahydro-4-quinolols and decahydro-4-quinolones

    The primary fraction of the total ion current in the mass spectra of decahydro-4-quinolones and 4-alkyl-2-methyldecahydro-4-quinolols containing various substituents in the 1, 4, and 7 positions is due to frag...

    N. S. Vul'fson, V. G. Zaikin, A. A. Bakaev… in Chemistry of Heterocyclic Compounds (1975)

  5. No Access

    Article

    Fragmentation of substituted 4-hydroxy-2-quinolones under the influence of electron impact

    The general principles of the mass-spectral disintegration of 4-hydroxy-2-quinoline derivatives containing various substituents attached to the nitrogen in the 3 position were established. It was found that th...

    V. G. Zaikan, Z. S. Ziyavidinova, N. S. Vul'fson in Chemistry of Heterocyclic Compounds (1974)

  6. No Access

    Article

    Comparative mass-spectrometric investigation of quinolizidine alkaloids and cytisine, sparteine, and matridine derivatives

    The low- and high-resolution mass spectra of pachycarpine, tetrahydrodesoxocytisine, matridine, α-isolupanine, tetrahydrocytisine, matrine, d-thermopsine, cytisine, and isosophoramine, as well as some of their st...

    N. S. Vul'fson, Z. S. Ziyavidinova, V. G. Zaikin in Chemistry of Heterocyclic Compounds (1974)

  7. No Access

    Article

    Correlation between the mass-spectrometric behavior and chromatographic mobility of epimeric 4-alkyl-1,2-dimethyl-trans-perhydroquinolol N-oxides

    The dependence between the Chromatographic mobility, the character of the disintegration under electron impact, and the configuration at C(4) was found for epimeric N-oxides of 1,2-dimethyl-4-ethyl-,-4-vinyl-, an...

    N. S. Vul'fson, V. G. Zaikin, A. A. Bakaev… in Chemistry of Heterocyclic Compounds (1973)

  8. No Access

    Article

    Structures of the products of the reaction of penilloic acids with acid anhydrides

    N4-Acylpenilloic acid lactam structures were assigned to the products of the reaction of penilloic acids with acid anhydrides on the basis of a chemical and physicochemical study.

    A. S. Khokhlov, E. M. Kleiner, V. N. Bochkarev… in Chemistry of Heterocyclic Compounds (1971)

  9. No Access

    Article

    Investigation of the reaction products of triacetonamine and ethyl cyanoacetate under knoevenagel reaction conditions

    Reaction of triacetonamine with ethyl cyanoacetate and ammonium acetate gives, in addition to the normal Knoevenagel reaction product (2,2,6,6-tetramethyl-4-ethoxycarbonylcyanomethylenepiperidine), its convers...

    E. S. Nikitskaya, E. I. Levkoeva, V. A. Puchkov… in Chemistry of Heterocyclic Compounds (1970)

  10. No Access

    Article

    Mass spectrometric study of 8-nitroisoxazolizidines

    The mass spectra of dimethyl- and methylphenyl-8-nitroisoxazolizidines have been studied, and the possibility of establishing the position of the substituents on the basis of an analysis of these spectra has b...

    B. V. Rozynov, N. S. Vul'fson, V. A. Puchkov… in Chemistry of Heterocyclic Compounds (1969)

  11. No Access

    Article

    The Claisen-Schmidt reaction with heterocyclic analogs of o-hydroxyacetphenone

    Claisen-Schmidt condensation of 4-hydroxy-3-acetyl-6-methylpyrid-2-one, and its N-methyl and N-phenyl derivatives with aromatic aldehydes is investigated, and it is shown that the products of this reaction are...

    N. S. Vul'fson, G. M. Sukhotin in Chemistry of Heterocyclic Compounds (1967)

  12. No Access

    Article

    Mass-spectrometer investigation of 3, 6-dialkyl-2, 5-diketopiperazines

    Analysis of mass-spectra of various 2, 5-diketopiperazines gives the basic fragmentation rules for their molecular ions, and the effects of nature and positions of substituents on the process.

    N. S. Vul'fson, V. A. Puchkov, Yu. V. Denisov… in Chemistry of Heterocyclic Compounds (1967)

  13. No Access

    Article

    Mass-spectrometer study of heterocyclic compounds

    A study is made of mass-spectra of aldehydes and carboxylic acid esters of indoles. It is shown that the mass-spectra can be used to differentiate α-carbonyl derivatives of indole from the β-analogs.

    N. S. Vul'fson, V. I. Zaretskii, A. V. Kisin… in Chemistry of Heterocyclic Compounds (1967)