Cycloaddition of perfluorovinyl ethers to dienes

Conclusions Cycloaddition of perfluorovinyl ethers to butadiene or piperylene led to 1-vinyl- or 1-propenyl-2-perfluoroalkoxy-2,3,3-trifluorocyclobutanes as mixtures of cis and trans isomers.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2372–2377, October, 1988.     

The oxidation of chlorine ions under the joint action of ozone and permanganate ions

The oxidation of chlorine ions in the system O₃ + MnO ₄ ^? + H⁺ + Cl^? with the formation of Cl₂ in the gas phase was studied. The phenomenon of transfer catalysis of the reaction between O₃ and Cl^? by the MnO ₄ ^? ion was observed (the products of the reduction of MnO ₄ ^? by the chlorine ion are oxidized by ozone to recover MnO ₄ ^? ). The rate of the formation of Cl₂ in the O₃ + MnO ₄ ^? + H⁺ + Cl^? system was higher than the sum of the corresponding rates in the oxidation of Cl^? by O₃ and MnO ₄ ^? separately. A scheme explaining the trends observed experimentally for the formation of Cl₂ and changes in MnO ₄ ^? concentration was suggested. The formation of MnO ₄ ^? in the oxidation of Mn³⁺ with ozone in acid media was studied.     

Macrocycle opening in formyl derivatives of benzocrown ethers under the action of methylamine

A new method for synthesizing nitrogen-containing podands by nucleophilic regioselective cleavage of the macrocycle in formyl derivatives of benzocrown ethers by heating with methylamine and methylammonium chloride has been developed. This reaction is the first example of crown ether opening by a nitrogen-containing nucleophile.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 950–953, May, 1995.     

Reactions of aromatic acetylenic ethers with triethylgermane

Conclusions The addition of Et₃GeH to the phenoxy- and phenylthioacetylenes under the influence of (Ph₃P)₃RhCl is both nonstereo- and nonregiospecific. The analogous reaction with 3-aroxy-1-propynes is stereospecific but nonregioselective.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2618–2620, November, 1982.     

Reactions of α-chloronitrones with unsaturated ethers

The Ag⁺ induced reaction of α-chloronitrones with unsaturated ethers goes in two parallel competitive directions. On the one hand cycloadducts like 3 are formed and on the other hand oxonium ions like 4. Formation of analogous oxonium compounds occurs also when α-alkoxynitrones are treated with Et₃O⁺BF₄^? in 1,2-dichloroethane. Formation of oxonium compounds with the enol-ethers is practically irreversible and leads to enol-ether fragmentation. With the saturated ethers compounds like 25 were formed and were used as a potential source of N-alkyl-N-vinyl-nitrosonium ions.     

Elemental fluorine. Part 24.[1]: Fluorination of ethers by fluorine and Selectfluor

Reactions of dialkyl ethers with either fluorine or Selectfluor™ led to the formation of unusual difluorinated polyether products in modest yields. A mechanism involving initial fluorination of the site adjacent to ether oxygen followed by elimination of hydrogen fluoride, reaction of the generated enol system with a further equivalent of fluorinating agent giving an oxonium system which reacts with water during aqueous work-up to lead eventually to the products observed, is suggested.     

Reactions of amines with a dimer of hexafluoropropene and with a perfluorovinyl sulfide prepared with hexafluoropropene

Some reactions of amines with a perfluorovinylsulfide, (CF₃)₂CFSC(CF₃)CFCF(CF₃)₂, prepared from hexafluoropropene (HFP) and sulfur [1] are compared to reactions of the same amines with the thermodynamic dimer of HFP, (CF₃)₂CCFCF₂CF₃. Many new ketenimines, eneamines, amidines, nitriles, and quinoline derivatives are reported.     

Metastable fragment ions from carbinolamine ethers

The secondary decomposition of fragment ions produced by electron impact of carbinolamine ethers was studied by mass analysed ion kinetic energy spectrometry. A new case was observed of ions of the same structure leading to the same fragments through different mechanisms competing in the metastable time frame and accompanied by a different partitioning of the excess energy (internal vs translational). The role of a fractional positive charge localized at saturated centres in the reactivity of these gaseous organic ions is discussed.     

Rearrangement of tetrazole ethers willi iodide ions

O to N Alkyl migration in 1-aryl-5-alkoxytetrazoles was observed on healing the substrates in the presence of sodium iodide. Unlike in similar rearrangements, methyl transfer did not occur in the presence of methyl iodide alone. Solvent effects were also investigated.     

Reactions involving shifting of the double bond in cyclic ethers

4-Methylenetetrahydropyran undergoes isomerization to 4-methyl-5,6-dihydropyran in the presence of sodium on aluminum oxide. Both pyrans are converted to a vinyl ether, viz., 4-methyl-2,3-dihydropyran, under the influence of iron pentacarbonyl.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 318–320, March, 1985.     

Reactions of acetals with alkyl 2-bromovinyl ethers

Summary A study was made of the condensation of benzaldehyde and acetaldehyde acetals with alkyl 2-bromovinyl ethers, as a result of which bromo ethoxy acetals of general formula RCH(OC₂H₅)CHBrCH(OR)₂ (R=C₆H₅ and CH₃) were formed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 282–285, February, 1965     

Reactions of fluoroalkanesulfonyl azides with cyclic vinyl ethers

The addition reactions of fluoroalkanesulfonyl azides to dihydropyran or dihydrofuran were studied. These reactions do not give the corresponding N-fluoroalkanesulfonyl azilidines but N-fluoroalkanesulfonyl-tetrahydropyranon-2-imines or N-fluoroalkanesulfonyl-tetrahydro-furano-2-imines. The reaction mechanism is discussed.     

Reactions of alkyl furfuryl ethers and sulfides with n-butyllithium

The direction of the reaction of alkyl furfuryl ethers and sulfides with n-butyllithium is in agreement with the results of basic H-D exchange in the same compounds: In the case of the ethers H-D exchange and metallation take place primarily in the free a position of the furan ring, whereas in the case of the sulfides these reactions take place primarily at the methylene group of the side chain located between the sulfur atom and the furan ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 744–746, June, 1984.     

Reactions of silylium ions with nucleophiles

Transformation of the diethylsilylium cation Et₂Si⁺H into ethyl-and dimethylsilylium ions EtSi⁺H₂ and Me₂Si⁺H in reactions with nucleophiles is induced by electron-donor compounds. Their activity increases in the order Bu₂O < BuOH < (Me₃Si)₂O < C₆H₆ and is determined by the structure of the intermediate adduct and electron density distribution in it. Qualitative estimation shows that the affinity of the tritiated diethylsilylium cation Et₂Si⁺T for a nucleophile increases in the order C₆H₆ < BuOH < Bu₂O < (Me₃Si)₂O. The higher affinity of the Et₂Si⁺H cation for hexamethyldisiloxane compared to dibutyl ether, at similar basicity of the nucleophiles, is attributable to the higher charge of the oxygen atom in (Me₂Si)₂O.