Intramolecular heterocyclization with accompanying exoiminization in the reaction of ammonia with 2-chloroperfluoro-1-cyclohexene-1-thiocyanate

The reaction of ammonia with 2-chloroperfluoro-1-cyclohexene-1-thiocyanate leads to 2-amino-7-iminoperfluoro-4,5,6-trihydrobenzo-1,3-thiazole (II) due to intramolecular heterocyclization in the Thorpe reaction with the concurrent exoiminization. Analysis of the IR spectra of (II) in CCl₄ and in the solid phase indicated that molecules of (II) in the crystal form hydrogen-bonded centrosymmetric dimers (D), which are in equilibrium with free molecules of (II) in solution.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2366–2370, October, 1991.The authors express their gratitude to D. I. Zagorevskii for taking the mass spectrum of (II) and to L. S. German for a useful discussion of this work.     

Structures of nitramine and isonitramine — Alkaloids of a new type from plants of the genusNitraria

The proof of the structures of two isomeric alkaloids — nitramine and isonitramine — from two species of plants of the genusNitraria is given. Their diastereoisomerism with respect to the C₇ asymmetric atom has been established. This is the first time that alkaloids with the structure of 2-azaspiro[5,5]undecan-7-ol have been found.     

Sulfenyl halides in the synthesis of heterocycles. 3. Interaction of perfluoro-1-ethyl-2-methyl-1-propenyl-iminochloromethanesulfenyl chloride with 1-allyl-2-methoxybenzene

Reaction of perfluoro-1-ethyl-2-methyl-1-propenyliminochloromethanesulfenyl chloride with 1-allyl-2-methoxybenzene in methylene chloride and nitromethane gives as the main products β-and β-chloro sulfides plus derivative of 2,3-dihydrobenzofuran. The reaction in nitromethane in the presence of lithium perchlorate gave a product of addition of sulfur-containing electrophiles to the double bond-a derivative of 1,3-thiazolidin-2-one-in preference to the cycloaddition product. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, 1558–1564, October, 2006.     

Polar cycloaddition of 2-pyridinetellurium trichloride to multiple bonds

A reaction of 2-pyridinetellurium trichloride with unsaturated hydrocarbons leads to [1,3]tellurazolo[3,2-a]pyridinium-4 derivatives — the products of polar cycloaddition of tellurium-containing electrophile at the multiple bond.     

Experimental detection of specular reflection of gamma quanta

Scattering of bremsstrahlung electron beam (E _e = 6.25 MeV) collimated with a vertical divergence δ_γ ≈ ±60 μrad and incident on the mercury surface at glancing angles α = −37, −83, and −140 μrad is studied on the 118-m-long path length. The specular reflection effect is detected in the spectral and angular distributions of γ quanta with energies up to 3 MeV. The reflection coefficients vary from 0 to ∼17% depending on the angles of incidence and the γ quanta energy.