Stereochemistry of the ionic hydrogenation of pentasubstituted 4H-thiopyrans and structures of the thiacyclohexanes obtained from them

The structure of 3,5-dimethyl-2,4,6-triphenylthiacyclohexane, obtained as a result of the ionic hydrogenation of the corresponding 4H-thiopyran with the CF₃COOH/HSi(C₂H₅)₃ couple, was established. It is shown that the stereochemistry of the ionic hydrogenation of 2,3,4,5,6-pentasubstituted 4H-thiopyrans, both those that disproportionate and those that do not disproportionate under the influence of trifluoroacetic acid, is the same.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 181–186, February, 1991.     

Effective charges on atoms of β-diketonates of metals obtained from x-ray electron spectroscopic data

Physicotechnical Research Institute of the Far Eastern State University. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 3, pp. 144–147, May–June, 1989.     

Peculiarities of the stereochemistry of the disproportionation,ionic, and catalytic hydrogenation of polysubstituted 4H-thiopyrans

The configuration of the thiacyclohexane obtained in the ionic and catalytic hydrogenation of 3,5-dimethyl-2,4,6-triphenyl-4H-thiopyran was established. It is shown that the stereochemistry of these reactions differs for penta- and tetrasubstituted 4H-thiopyrans in that the stereochemistry of the cited processes and the stereochemistry of disproportionation are the same for each of the polysubstituted 4H-thiopyrans.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 910–911, July, 1987.     

Condensation of aldehydes and ketones

The alkaline condensation of -aceto-and -propionaphthalenes with furfural has given, respectively, 2-(-furfuryl)-1, 3-di(-naphthoyl)-propane and 3-(-furyl)-2,4-di(-naphthoyl)pentane; both -diketones have also been obtained by the Michael condensation. Under more severe conditions, two molecules of furfural condense with three molecules of -acetonaphthalene to form 2, 4-di(-furyl)-1, 3, 5-tri(-naphthoyl)pentane. Under similar conditions, benzaldehyde exhibits only a feeble capacity for triketone condensation with -acetonaphthalene. The condensation of -propionaphthalene with furfural has given the new compound furylidenepropionaphthalene. It has been shown that both under the conditions of the improved Chichibabin pyridine synthesis and under the conditions of the Leuckhardt reaction, 3-(-furyl)-1, 3-di(-naphthoyl)propane gives 4-(-furyl)-2, 6-di(-naphthyl)pyridine.     

An unusual product of the reaction of 1-phenyl-3-(3,4-dimethoxyphenyl)-3-(2-oxocyclohexyl)-1-propanone with hydrogen sulfide and acids: 2α-phenyl-2,4-ortho-(14,15-dimethoxybenzo)-cis-1-thiadecalin

The reaction of 1-phenyl-3-(3,4-dimethoxyphenyl)-3-(2-oxocyclohexyl)-1-propanone with hydrogen sulfide and acids gives an intramolecular rearrangement product, 2-phenyl-2,4-ortho-(14,15-dimethoxybenzo)-cis-1-thiadecalin in addition to the usual products of disproportionation of intermediate 2-phenyl-4-(3,4-dimethoxyphenyl)-5,6-tetramethylene-4H-thiopyran, namely, 5,6-tetramethylenethiopyrilium salts and 2-phenyl-4-(3,4-dimethoxyphenyl)-cis-1-thiadecalin. The configurational and conformational assignments for the sulfides, their sulfoxides, and sulfones were made by ¹³C NMR spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 199–205, February, 1986.     

Unsaturated 1,5-diketones and their halogen-substituted derivatives — Preparation and use in the synthesis of heterocycles

Published data and the results of the authors' own research on methods for the production of unsaturated 1,5-diketones and halogen-substituted 2-pentene-1,5-diones and their use in the synthesis of difficulty obtainable pyrylium, 3,5-dichloropyrylium, and 3-chlorothiopyrylium salts, aroylfurans, 40-chloroaroylfurans, isoxazolines, pyrazolines, 3,5-dichloropyridines, 1,4-tetramethylenebispyridines, and others are summarized. Aspects of the structure of 2-pentene-1,5-diones and their 2,4-dichloro-substituted analogs and features of their heterocyclization are discussed in comparison with pentane-1,5-diones and their 2,4-dichloro-substituted derivatives.N. G. Chernyshevskii Saratov State University, Saratov, K. A. Fedin Saratov State Pedagogical Institute, Saratov. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1299–1319, October, 1996. Original article submmited June 8, 1995     

Saturated nitrogen-containing heterocycles. 11. The synthesis and structural studies of octahydroindolylalkanols

A catalytic synthesis was carried out for 3-(1-R-2-octahydroindolyl)alkanols using nickel promoted by ruthenium, Raney nickel, and Raney cobalt previously treated with acetic acid. An x-ray diffraction structural study of the acid tartrate of 3-(1-methyl-2-octahydroindolyl)-1-propanol gave the absolute configuration and conformational and structural features of the cation and tartrate anion.For Communication 10, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 66–70, January, 1985.     

Study of the mechanism of recyclization of furans into thiophenes and selenophenes in conditions of acid catalysis. 6. Experiments with labeled atoms. Quantum chemical calculations of intermediates of recyclization and hydrolysis

The reaction of 2-methyl-5-R-furans (R=Me, Bu, 2,2-pentyl-2-methylpentyl) with H₂ ¹⁸O was investigated. Furans and the corresponding 2,5-alkanediones containing the¹⁸O isotope were obtained. The general characteristics of the recyclization and isotope exchange reactions were established. A kinetic study of recyclization of 2,5-dimethylfuran with¹⁶O and¹⁸O into 2,5-dimethylthiophene was conducted. A reverse kinetic isotope effect was found. The schemes of the mechanisms of these processes were refined based on the experimental data and quantum-chemical calculations of the recyclization and hydrolysis intermediates.See [1] for Communication 5.Scientific-Research Institute of Chemistry, N. G. Chernyshevskii Saratov State University, Saratov 410026. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1035–1042, August, 1997.     

Saturated nitrogen-containing heterocycles. 14. Synthesis and three-dimensional structures of n-r-dicyclopenta[b,e]piperidines

The catalytic hydroamination of threo-methylenedicyclopentanone using ammonia, methylamine, and monoethanolamine as the aminating agents proceeds stereospecifically with the formation of N-R-cis-syn-cis-dicyclopenta[b,e]piperidines (R=H, CH₃, CH₂CH₂OH). The structures of the latter were proved by ¹³C NMR spectroscopy. The molecular structure of N-(-hydroxyethyl)cis-syn-cis-dicyclopenta[b,e]piperidinium acid tartrate was investigated by x-ray diffraction analysis, and the absolute configuration of its chiral centers was determined.See [1] for Communication 13.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1094–1099, August, 1988.