C-alkylation of 3-methyl-1-phenyl-5-pyrazolone by hexafluoroacetone and its imines

Conclusions Regiospecificity was demonstrated for C-alkylation in the reactions of 3-methyl-1-phenyl-5-pyrazolone with hexafluoroacetone and the trifluoroacetylimine and benzenesulfonylimine of hexafluoroacetone at C⁴ of the heterocycle.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 684–686, March, 1987.     

Biodegradation of aromatic compounds by the yeast-like fungus Trichosporon cutaneum

The biodegradation reactions of veratryl- and guaiacylpropane compounds modeling structural fragments of the lignin macromolecule by the yeast-like fungusTrichosporon cutaneum D-46 have been investigated. It has been shown that the enzyme complex ofT. cutaneum is capable of catalyzing a series of reactions of the biotransformation of arylpropane substrates, namely: oxidation, the cleavage of the C-C bond of the propane chain, demethylation, and decarboxylation. The action of the enzymes was shown most actively in the case of substrates having an unsubstituted phenolic hydroxy group.Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk. Institute of Microbiology, Belorussian Academy of Sciences, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 558–564, September–October, 1992.     

Electrical transport and magnetic ordering in R 2Ti3Ge4 (R=Dy, Ho and Er) compounds

New R ₂Ti₃Ge₄ (R=Dy, Ho and Er) intermetallic compounds have been synthesized and characterized by X-ray diffraction and low temperature ac magnetic susceptibility, electrical resistivity and thermoelectric power measurements were carried out. The compounds crystallize in the parent, Sm₅Ge₄-type orthorhombic structure (space group Pnma) and lanthanide contraction is observed as one moves along the rare-earth series. The changeover from paramagnetic to antiferromagnetic phase happens at low temperatures and the ordering temperature scales with the de Gennes factor. The electrical resistivity is metallic with a negative curvature above 100 K. Thermopower displays a weak maximum at temperatures less than 50 K signifying the possible phonon and magnon drag effects.     

Asymptotic methods in the theory of nonlinear random oscillations

We study applications of asymptotic methods of nonlinear mechanics and the method of Fokker-Planck-Kolmogorov equations to the investigation of random multifrequency oscillations in systems with many degrees of freedom.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 46, No. 8, pp. 1011–1016, August, 1994.This work was supported by the Ukrainian State Committee on Science and Technology.     

An unusual reaction of 1,1-dicyano-2,2-bis(trifluoromethyl)ethylene

Translated from Izvestiya Akademii Nauk SSSR, Seriya KMmicheskaya, No. 6, pp. 1451–1452, June, 1988.     

Reaction of methyl trifluoropyruvate with aryl amines

Conclusions We have found a novel reaction of primary and some secondary aryl amines with methyl trifluoropyruvate, which yields derivatives of 3-hydroxy-2-oxo-3-trifluoromethylindoline.For preliminary communication, see [1].Translated from Izvestiya Akademii-Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2080–2085, September, 1986.     

Electronic structure of imidazole,its tautomerism and mechanism for H-D exchange in aqueous solution

Conclusions It has been shown using quantum-chemical methods that an intramolecular mechanism for isomerization of imidazole in the gas phase and in aqueous solution is energetically unfavorable but an intermolecular mechanism can occur via stages involving the formation of protonated and carbene structures.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2779–2783, December, 1988.