Rheological Characteristics of Moist Microcrystalline Cellulose Pastes

The suitability of the contact method for drying moist finely ground product classed, according to its properties, with pastes was considered. The rheological characteristics of microcrystalline cellulose pastes were studied experimentally in relation their moisture content. The study was based on the Metzner procedure with the moist product with mechanical stirrers in a mixer.     

Synthesis and study of tautomeric properties of 2-(5-R-2-furyl)thiazolin-4-ones

Compounds were synthesized by reaction of 5-R-2-cyanofurans with thioglycolic acid, which, according to IR, PMR, and mass spectrometric data, exist in the form of two tautomers, 4-hydroxythiazole and thiazolin-4-one.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 404–409, March, 1987.     

Enantioselective reduction of C=O and C=N bonds by TADDOL-containing aluminum hydride reagents based on NaAlH4 and AlH3

Prochiral substrates (alkyl aryl ketones, cyclopropyl methyl ketone, 1-indanone, 1-tetralone, ethyl 2-oxo-4-phenylbutyrate, and N-(diphenylphosphinyl)acetophenoneimine) were subjected to asymmetric reduction with aluminum hydride reagents, which were prepared by modifications of NaAlH₄ or AlH₃ with chiral ,,","-tetraaryl-1,3-dioxolane-4,5-dimethanols (TADDOL). The effects of the nature of the substituents in TADDOL, the structure of the prochiral substrate, and the reaction conditions on the stereochemistry of reduction were investigated. The highest enantioselectivity (70—90% ee) was achieved upon reduction of alkyl aryl ketones and N-(diphenylphosphinyl)acetophenoneimine with NaAl(TADDOLate)H₂ in THF or diglyme at a temperature from –70 to –20 °C. The mechanism of asymmetric induction in the reduction reactions of ketones with aluminum hydride reagents is discussed. The stereochemical results of reduction were explained by comparing three-dimensional models of the most probable transition states.     

Explicitly solvable model of Mössbauer scattering

An explicitly solvable model of Mössbauer scattering of rays by a nucleus bound in a harmonic-oscillator potential is constructed. The probability of elastic scattering, which is proportional to the Debye—Waller factor, is calculated in the framework of the explicitly solvable scattering problem. It is assumed that the rms deviation x of the nucleus and the photon wave numberk satisfykxE /E , whereE andE are typical energy levels of the photon and the oscillator states.St Petersburg State University. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 95, No. 3, pp. 439–430, June, 1993.     

Spectral properties of one-dimensional disperse crystals

The connection between the spectral characteristics of the one-dimensional Schrödinger operator with periodic potential, asa, and the spectral characteristic of the Schrödinger operatorl(y)=–y+q(x)y with a decreasing potentialq(x) is studied.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 133, pp. 197–211, 1984.     

Reaction of 4-methyl-5,6-dihydro-2h- and 4-methylenetetrahydropyrans with phenylsulfinyl chloride

4-Methyl-5,6-dihydro-2H- and 4-methylenetetrahydropyrans undergo an ene- type reaction with phenylsulfinyl chloride in the presence of ZnCl₂ to give the corresponding allylic sulfoxides.October Revolution Fortieth Anniversary, Bashkir State University, UfaTranslated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1446–1447, June, 1990.     

Molecular characteristics of subfractions of laminarin

Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center of the Russian Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 296–298, March–April, 1994.     

First synthesis of α-aminophosphonates from natural porphyrin derivatives by the Kabachnik—Fields reaction

A preparative procedure is proposed for the synthesis of α-aminophosphonates of natural porphyrins by the microwave-assisted Kabachnik—Fields reaction.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 256–259, January, 2005.