Synthesis of N-substituted pyrrole-3-carbaldehydes by hydroformamination of 2,5-dimethoxy-2,5-dihydrofuran

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, p. 1285, September, 1990.     

Synthesis of diamides from 1,4-benzodioxane-2- and isochroman-1-carboxylic acids

1,4-Benzodioxane-2-carboxylic acid and isochroman-1-carboxylic acid were treated with thionyl chloride, and the resulting acid chlorides reacted with p-aminobenzoic acid in dioxane in the presence of pyridine to produce the corresponding amido acids. The latter were converted into acid chlorides which were brought into reaction with various amines to obtain a number of new diamides.     

Mutual modification of silver-nanoparticle plasmon resonances and the absorptive properties of polymethine-dye molecular layers on a sapphire surface

Extinction spectra of a hybrid material comprised of molecular layers of polymethine dyes and granulated silver films preliminarily deposited onto sapphire substrates are studied experimentally. Specific features of the dye layer composition and broadening of plasmon absorption bands are discussed. In hybrid samples, both an increase and a decrease in the silver-nanoparticle plasmon resonance frequency upon spreading of dyes have been observed, as well as a considerable increase in the dye molecule absorption. Possible mechanisms of the phenomena are discussed.     

Transformations of 2,2-dialkyl-4-pyranones in the vapor phase

Conclusions It was established that 2,2-dialkyl-4-pyranones can be selectively converted in the vapor phase to aliphatic ketones on catalysts that contain Group VIII metals.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 912–913, April, 1981.     

A rearrangement of 3-(1-hydroxy-1-organylmethyl)-2,5-dimethoxytetrahydrofurans

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, p. 2389, October, 1989.     

Conformational analysis and stereochemistry of the reduction of 2-alkoxymethyl-4-oxopiperidines

The isomer with an axially oriented alkoxymethyl group predominates in the equilibrium mixture of 1-aklyl-2,5-dimethyl-2-alkoxymethyl-4-piperidones investigated under both alkaline and acidic equilibrium conditions, and its percentage increases as the volume of the alkoxy group increases in the order Me, Et, iso-Pr. The reduction of 4-ketopiperidines that contain a polar function in the 2 position follows the same principles as those that obtain when it is absent, i.e., exclusively the equatorial alcohols are obtained in the case of reduction with lithium and ethanol in liquid ammonia, whereas primarily the axial alcohols are obtained in the case of reduction with sodium borohydride. The selectivity of the reduction increases on passing from the free bases to the hydrochlorides.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 503–506, April, 1979.     

Three-dimensional structures of cyclic 2,2-bis(hydroxymethyl)-tetrahydrofuran acetals

2-Substituted spiro[1,3-dioxane-5,2-tetrahydrofurans] were obtained from 2,2-bis (hydroxymethyl) tetrahydrofuran, and their three-dimensional structures were investigated by ¹H and ¹³C NMR spectroscopy. The tetrahydrofuran ring lies in the plane of symmetry of the 1,3-dioxane ring with an equatorial orientation of the oxygen atom.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 162–166, February, 1984.     

Investigation of the stereodirection of the Ritter reaction. Crystalline and molecular structure of N-(2-phenethyl)-4-methylpiperid-4-ol and N-(2-phenethyl)-4-methyl-4-acetamido-piperidine

The stereodirection of the Ritter reaction of N-(2-phenethyl)-4-methylpiperid-4-ol to the corresponding amide has been studied. X-ray analysis has shown that the reaction occurs with retention of the configuration about atom C₄ of the piperidine ring. Attempts are made to explain the stereodirection of the direction.A. L. Mndzhoyan Institute of Fine Organic Chemistry, Armenian Academy of Sciences, Yerevan 375014. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1391–1396, October, 1994. Original article submitted September 28, 1994.     

Reaction mechanism for formation of condensed thienopyrans and thienothiopyrans

The formation of 2-amino-3-cyanothiophenes has been studied. It has been shown that the intermediates in the synthesis are the Knoevenagel type ,-unsaturated nitriles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 395–397, March, 1987.     

Synthesis of acetonylmalonaldehyde and its interaction with aminoazoles

Acetonylmalonaldehyde (1) was obtained for the first time by hydrolysis of 2,5-dimethoxy-5-methyltetrahydrofuran-3-carbaldehyde. The interaction of1 with 3-amino-5-methylpyrazole, 3-amino-1,2,4-triazole, 2-aminobenzimidazole, and 5-aminotetrazole results in the formation of functionally substituted azolopyrimidines. Deceased. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1226–1228, June, 1997.