Nitrile Oxide Approach to the Synthesis of Δ23-22-Oxo Steroids

^{2 3}-22-Oxo steroids were synthesized via 1,3-dipolar cycloaddition of steroidal nitrile oxides to low-molecular dipolarophiles. Cycloaddition of 2-propynyl bromide to 20-carbonitrile oxide, followed by hydrogenation of the isoxazole derivative thus formed gave 22-enamino-24-keto steroid. The latter was then converted into the target enones via several pathways. Compounds with unnatural configuration of the C^{2 0} atom can also be obtained. ^{2 3}-22-Oxo steroids were also synthesized through isoxazole derivatives.     

Crystal structure of tris(ethylenediamine)cobalt(III) (aqua)hexachloromercurate(II) chloride [Co(En)3]2[Hg2(H2O)Cl6]Cl4

The compound [Co(En)₃]₂[Hg₂(H₂O)Cl₆]Cl₄ (I, En is ethylenediamine) has been synthesized and studied by X-ray diffraction. The crystals of I (a = 21.8745(14) Å, b = 10.6008(6) Å, c=15.4465(12) Å, space group Pna2₁) consist of tris(ethylenediamine)cobalt(III) complexes (the unit cell contains two [Co(En)₃]³⁺ cations of opposite chirality). [Hg₂(H₂O)Cl₆]^2? anions, and isolated chloride ions. The complex anion consists of the tetrahedral [HgCl₄]^2? group (Hg-Cl, 2.44–2.56 Å) and the hydrated molecule [Hg(H₂O)Cl₂] (Hg-Cl, 2.301 and 2.308 Å; Hg-O, 2.788 Å) combined by weak Hg-Cl interactions (2.915 and 3.220 Å).     

Nonlinear Effects in a Viscous Wave Field Excited by a Finite-Size Plate

Technical Physics - We have numerically investigated nonlinear nonstationary velocity and pressure fields in a viscous incompressible fluid near an oscillating absolutely rigid plate of an...     

Thermodynamics of the evaporation of dimethylzinc, dimethylselenium, and their equimolecular solutions

Using data on the calorimetry of evaporation and the temperature dependence of vapor pressure, we establish that an equimolecular solution dimethylzinc-dimethylselenium acts as a single-component system in the temperature interval of 273?C346 K in the liquid phase and dissociates into its constituents in transitioning to the gas phase.