Synthesis and Asymmetric Oxidation of (Caranylsulfanyl)‐1H‐imidazoles

For the first time 2‐(cis‐caran‐4‐ylsulfanyl)‐1H‐imidazole, 1‐methyl‐2‐(cis‐caran‐4‐ylsulfanyl)‐1H‐imidazole, and 2‐(cis‐caran‐4‐ylsulfanyl)‐1H‐benzimidazole (carane=3,7,7‐trimethylbicyclo[4.1.0]heptane) were synthesized, and the asymmetric oxidation of these compounds was also carried out. It was shown that oxidation by the Bolm system and the modified system of Sharpless lead to corresponding sulfoxides with de values of 91–100%.     

Asymmetric oxidation of verbenone ethylene dithioacetal

Asymmetric oxidation of verbenone ethylene dithioacetal with m-chloroperoxybenzoic acid at different substrate-to-oxidant ratios in methylene chloride at ?10°C gave previously unknown (1S,1′S,2S,3′S,5S)-4,6,6-trimethylspiro[bicyclo[3.1.1]hept-3-ene-2,2′-[1,3]dithiolane] 1′,3′-dioxide, (1S,2S,3′S,5S)-4,6,6-trimethylspiro[bicyclo[3.1.1]hept-3-ene-2,2′-[1,3]dithiolane] 1′,1′,3′-trioxide, and (1S,5S)-4,6,6-trimethylspiro[bicyclo-[3.1.1]hept-3-ene-2,2′-[1,3]dithiolane] 1′,1′,3′,3′-tetraoxide whose structure was determined by X-ray analysis.     

Asymmetric sulfoxidation of phenacyl phenyl sulfide using chiral vanadium(IV) complexes

Asymmetric sulfoxidation of phenacyl phenyl sulfide was performed in the presence of bis(acetylacetonanto) oxovanadium(IV) complexes with chiral Schiff bases, which were generated in situ. Chlorine dioxide and hydrogen peroxide as oxidants were compared.     

Asymmetric synthesis of new optically active sulfinamides of menthane series and their derivatives

Asymmetric syntheses were performed of neomenthanesulfinamide in the yield of 60% and de 74%, of neomenthanesulfinaldimines and N-substituted neomenthanesulfinamides in 22–80 and 40–90% yields respectively.     

Magnetic structure of Ce<Subscript>2</Subscript>Fe<Subscript>17 − <Emphasis Type="Italic">x</Emphasis></Subscript>Mn<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> intermetallic compounds

The magnetic structure of intermetallic compounds Ce₂Fe_{17 − x} Mn _x (0 ≤ x ≤ 3) was studied using neutron diffraction. The neutron diffraction patterns measured at 4.2 K contain satellites indicating a modulated structure with the wave vector k = [0, 0, τ]. As the concentration x increases, the value of τ increases, while the average magnetic moment of Fe/Mn atoms decreases. A change in the magnitudes of the average magnetic moment and wave vector k is explained by competition between exchange interactions at distances of nearest neighbor transition element atoms.     

Simulation of structure-related mechanical characteristics of disperse systems under dynamic conditions

Results of simulating the structure-related rheological properties of disperse systems under dynamic conditions are reported. Computer-simulation data on the influence of some parameters on the viscosity and structure-related characteristics of dispersions agree with analytical dependences and experimental results. Problems concerning the dynamic equilibrium of dispersions subjected to shear deformation, as well as disturbance of equilibrium, are considered. Results of computer simulating the percolation characteristics of dispersion microstructure under dynamic conditions are reported.     

Insect pheromones and their analogues XLVIII. A convenient synthesis of the 10E,12Z- and 10E,12E- isomers of hexadecadien-1-ol and of hexadeca-10E,12Z-dienal — Components of the sex pheromone of the silkworm moth

The 10E,12Z- and 10E,12E- isomers of hexadecadien-1-ol and of hexadeca-10E,12Z-dienal — components of the sex pheromone of the silkworm mothBombyx mori — have been synthesized from the readily available octa-2E,7-dien-1-ol.     

Hydroalumination of alkenes by the LiAlH4 · 3AlBr3 system

The hydroalumination of a series of alkenes and some fused aromatic hydrocarbons by the LiAlH₄ · 3AlBr₃ system in low-polar solvents was studied. Alkenes with mono-, di-, tri-, and tetraalkyl substituted, mono- and diaryl substituted double bonds and anthracene react at room temperature to give the corresponding dibromoaluminoalkanes in high yields. Benzylidenefluorene, tetraphenylethylene, naphthalene, and phenanthrene do not undergo hydroalumination under these conditions. Camphene, bicyclo[3.2.1]oct-2-ene, and norbornene afford the corresponding organoaluminum compounds with high stereoselectivity. Oxidation and halo- and acyldemetallation of the resulting alkyl- and arylalanes were carried out.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1637–1642, September, 1993.     

Synthesis of new fluorine-containing pyrazolo[3,4-<Emphasis Type="Italic">b</Emphasis>]pyridinones as promising drug precursors

Methods for the synthesis of 4-R-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones (R = CF₂SAr and 4-CFHSAr) were developed. The derivatives with R = CF₂SAr were obtained by both heterocyclization of 1-substituted 5-aminopyrazoles with ethyl 4,4-difluoro-3-oxo-4-phenylsulfanylbutanoate and replacement of the Br atom in 4-bromodifluoromethyl-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones by sodium arenethiolates. The fragment 4-CF-HSAr was introduced by replacement of the Cl atom in 4-chlorofluoromethyl-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones by sodium arenethiolates. Oxidation of 4-CF₂SPh-6,7-dihydro-1H-pyrazolo[3,4-b]pyridin-6-ones gave the corresponding sulfoxides; their structures were confirmed by X-ray diffraction data.