13C NMR spectra of biologically active compounds.

The¹³C spectra of 25 new substituted cyclopropanes of the pyrethoid series have been investigated and a stereochemical assignment has been made of the stereoisomers formed. As the criterion for stereochemical assignment it is proposed to use the values of the chemical shifts for the -carbon atoms of the substituents in the cyclopropane ring.Institute of Chemistry, Bashkir Branch, USSR Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 266–272, March–April, 1989.     

Nonlinear absorption of femtosecond light pulses under conditions of multiphoton resonances in solids

A theory of nonlinear absorption of femtosecond light pulses by bulk crystals and nanostructures of differing dimensionality is developed. The pulse width is assumed to be small compared to the relaxation times of the electron and hole momenta. Expressions for the absorbed energy under conditions of multiphoton resonance are derived for transitions between discrete or band-related electron states and between sub-band states of size quantization in quantum wells and quantum wires. The dependence of the absorbed energy on the multiphoton resonance detuning and pulse width is analyzed.     

A facile synthesis of spiro macrocarbocycles via the cycloalumination reaction of cyclic alkynes and alkadiynes

Zirconium-catalyzed cycloalumination of cycloalkadiynes assisted by Et₃Al, subsequent treatment of the in situ generated tricyclic dialuminum compounds with BrCH₂OMe and finally cyclopropanation of the obtained dispiro cyclopropyl dimethylene macrocarbocycles with Et₃Al-CH₂I₂ represents an efficient one-pot synthetic approach to prepare di- and tetraspiro cyclopropane-containing macrocarbocycles in very high yields.     

Synthesis and transformations of metallacycles

The Cp₂ZrCl₂-catalyzed reaction of arylolefins (styrene,o- andp-methylstyrenes,trans-stilbene, 1,4-diphenyl-1,3-butadiene) with AlEt₃ resulting in mono- and disubstituted alumacyclopentanes and substituted alumacyclopropanes was studied. The yield and ratio of cyclic organoaluminum compounds depend on the structure of the initial arylolefins and conditions of cycloalumination.     

Synthesis and transformations of metallacycles 36. Cycloalumination of macrocyclic diacetylenes with Et<Subscript>3</Subscript>Al catalyzed by Cp<Subscript>2</Subscript>ZrCl<Subscript>2</Subscript>

Cycloalumination of macrocyclic diynes with Et₃Al catalyzed by Cp₂ZrCl₂ resulted in unsaturated bi- and tricyclic mono- and dialuminacarbocycles in 76–91% yields.     

Alk-2-yn-1-amines in the synthesis of substituted quinolines in the presence of palladium complexes

An effective one-step procedure has been developed for the synthesis of 4- and 2,3,4-substituted quinolines via reaction of o-iodoaniline with alk-2-yn-1-amines in the presence of Pd(OAc)₂ as catalyst.     

Synthesis of fullerene epoxide (C<Subscript>60</Subscript>O) by oxidation of fullerene C<Subscript>60</Subscript> with oxygen catalyzed by Mn(III), Ni(II), and Co(II) acetylacetonates

A procedure has been developed for the synthesis of fullerene monoepoxide C₆₀O via liquid-phase oxidation of fullerene C₆₀ in the presence of accessible catalysts [(Mn(acac)₃, Ni(acac)₂, and Co(acac)₂].     

Cycloalumination of allylbenzenes with triethylaluminum in the presence of Cp<Subscript>2</Subscript>ZrCl<Subscript>2</Subscript>. One-pot synthesis of 2-benzylbutane-1,4-diols as precursors of dibenzylbutane lignans

One-pot synthesis of 2-[(hydroxy- and methoxyphenyl)methyl]butane-1,4-diols in an overall yield of 60–65% by cycloalumination of allylbenzenes (4-allyl-1-methoxybenzene, 4-allyl-1,2-dimethoxybenzene, 5-allyl-2-methoxyphenol, and 5-allyl-1,2,3-trimethoxybenzene) with triethylaluminum in the presence of Cp₂ZrCl₂ is reported for the first time. The developed procedure opens a new synthetic route to practically important β-substituted butane-1,4-diols that are precursors to dibenzylbutane lignans.     

Electroweak Nucleon Decays in a Superstrong Magnetic Field

We study the influence of a magnetic field on the electroweak processes of nucleon decay in a degenerate ideal gas of neutrons, protons, and electrons situated in an external superstrong constant and homogeneous magnetic field with effects due to the interaction of nucleon anomalous magnetic moments with the magnetic field taken into account. For different values of the chemical potentials of degenerate fermions, we obtain expressions for probabilities of electroweak processes, which are assumed to be responsible for the chemical equilibrium in the central domain of a neutron star with a frozen superstrong magnetic field. We show that the difference between the neutron decay probabilities in the presence of a magnetic field B ≪ 10¹⁷ G and without this field is completely determined by changing the phase volume of electron states. We discuss the process of proton decay into a neutron, positron, and neutrino. This process is energetically allowed only when the interaction of nucleon anomalous magnetic moments with a superstrong magnetic field is taken into account. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 145, No. 1, pp. 108–122, October, 2005.