V. S. Bogdanov

Aryl-NNO-azoxy-α-nitroalkanes

Two methods of synthesis of aryl-NNO-azoxy-α-nitroalkanes bearing either one or two reactive hydrogen atoms α to the azoxy and nitro groups are described. These methods involve protection of the latter by easily removable groupings, those used being acetoxy-methyl and acetal fragments. The regiochemical nature of the diazene oxide groupings in aryl-NNO-azoxy-α-nitroalkanes obtained by oxidation of the appropriate diazenes has been established by heteronuclear NMR and x-ray structural examination. Some of the chemical properties of these diazene oxides have been examined.

Synthesis of heterocycles on the basis of products of addition of polyhaloalkanes to unsaturated systems.

Oximes of 3,3-dichloropropenal and 4,4,4-trifluoro-3-chloro-1-butenal were obtained on the basis of products of free-radical addition of CCl4 and CF3CCl3 to vinyl butyl ether. Generation of the corresponding nitrile oxides from these oximes and reaction of the nitrile oxides in situ with vinyl butyl ether, phenylacetylene, and propargyl alcohol via the scheme of 1,3-dipolar cycloaddition are proposed as a method for the synthesis of isoxazoles containing β,β-dichlorovinyl and β-trifluoromethyl-β-chlorovinyl substituents in the 3 position.

Synthesis of heterocycles based on the products of the addition of polyhalogenoalkanes to unsaturated systems. 3. Structure and stereochemistry of substituted N-furylformamidines

It was established with the aid of the 1H, 13C, and 15N NMR spectra as well as the x-ray structural analysis that the substituted furylformamidines, which are key compounds in the synthesis of furo[2,3-d]pyrimidines, are E-isomers of N(1) -furyl-N(2) -R-formamidines (R=H, Alk, Ar), independently of the nature of the substituent at the second N atom, and occur mainly in the form of the antiplanar rotamers.

15N and13C NMR spectral study of the Z, E isomerism of thiophene aldoximes

Chemical shifts and coupling constants were determined in the15N and13C NMR spectra of thiophene aldoximes with natural isotope content. The effects of Z, E isomerism on the spectral parameters were determined. The2J15N.H and1J13C.H coupling constants in the CH=NOH fragment are characteristic.

Transformed steroids. 171. Heterocyclization in the 16α,17α-epiminopregn-5-ene-3β,21-diol-20-one series

Conclusions1.The transformation of 21-0,N-isopropylidene derivatives of 16α,17α-epiminopregn-5-ene-2β,21-diol-20-one into 20-0,N-isopropylidene derivatives of 16α,17α-epiminopregn-5-ene-3β,20-diol-20-one was discovered, and, based on this, a new variant of the synthesis of 16α,17α-epiminopregn-5-ene-3β,21-diol-20-one-3′,21-diacetate was proposed.2.A new class of steroids with additional tetrahydrofuran and 1′,3 -imidazolidine-2′thione rings E and F, respectively, was synthesized.