Lactam and amide acetals. 52. Reaction of dimethylformamide diethylacetal with 2,2-dimethyl-4,6-dioxo-1,3-dioxane (Meldrum's acid)

Depending on the conditions of carrying out the reaction of dimethylformamide diethylacetal with the Meldrum's acid, either 2,2-dimethyl-4,6-dioxo-5-(N,N-dimethyl-aminomethylene)-1,3-dioxane or N,N,N¹N¹-tetramethylformamidinium salt of 2,2-dimethyl-4,6-dioxo-5-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)methylene-1,3-di-oxane are formed. The two compounds can react with primary amines to form N-substituted 2,2-dimethyl-4.,6-dioxo-5-aminomethylene-1,3-dioxanes.For Communication 51, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 184–187, February, 1988.     

13C,13C coupling constants of conjugated dienes

One bond ¹³C,¹³C- and ¹³C,¹H-coupling constants have been measured for some 1,2-dimethylene-cycloalkanes, as well as for 2,3-dimethylbuta-1,3-diene and methylenecyclobutane. The results for 2,3-dimethylbuta-1,3-diene confirm the findings for buta-1,3-diene, i.e. that J(C-1, C-2) is smaller for the diene than for the correspondingly substituted monoene. No differences have been found between the ¹J(CC) exocyclic coupling constants of the dimethylene and monomethylene cycloalkanes.     

NMR spectra of cyclic nitrones. 4. Synthesis and 13C NMR spectra of 4H-imidazole N-oxides and N,N-dioxides

4H-Imidazole 1,3-dioxides and 4H-imidazole 3-oxides were obtained by oxidation of 1-hydroxy-3-imidazoline 3-oxides and 1-hydroxy-3-imidazolines with lead and manganese dioxides or the stable nitroxyl radical, while 4H-imidazole 1-oxides were obtained by thermal decomposition of 1-acetoxy-3-imidazoline 3-oxides. Facile oxidation of the ethyl group in 5-ethyl-4H-imidazole 1,3-dioxide and the formation of 5-acetyl-4H-imidazole 1,3-dioxide and 5-acetyl-4H-imidazole 3-oxide were observed. It is shown that a strictly determined region of chemical shifts of the C(₂), C(₅), and C(₄) atoms is characteristic for each group of 4H-imidazole N-oxides in the ¹³C NMR spectra; this makes it possible to clearly establish the position of the N-oxide oxygen atom.See [1] for Communication 3.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1640–1648, December, 1988.     

Synthesis and nonchair conformations of 2,2-disubstituted 4,4-dimethyl-1, 3-dioxanes

The fundamental possibility of the synthesis of 2-substituted 1,3-dioxanes by reaction of 1,3-dioxanium perchlorates with organometallic compounds is demonstrated. A method for the synthesis of acyl derivatives of heterocycles was developed on the basis of these compounds. The existence of 2,2,4,4-substituted 1,3-dioxanes in the twist conformation was shown by ¹H NMR spectroscopy; the twist conformation is explained by the effect of nonbonded 1,3-syn-axial interactions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1172–1179, September, 1978.     

Heterocyclic analogs of pleiadiene. 50. Sulfonation of perimidines,perimidones, and 2,3-dihydroperimidines

The action of concentrated sulfuric acid on perimidine and 2-substituted perimidines, 1,3-dimethylperimidinium perchlorate, and the 1,3-dimethyl derivatives of perimidone and 2,3-dihydroperimidine gave the 6(7)-sulfonic acids of these compounds.See [1] for communication 49.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 691–696, May, 1980.     

Enthalpies of sublimation and fusion of monophenylurea and diphenyl-1,3 urea

The sublimation enthalpies of monophenylurea (MPhU) and diphenyl-1,3 urea (1,3-DPhU) have been derived from the dependence of their vapour pressures on temperature, as measured by the torsion-effusion method. Values obtained are: 136 kj mol⁻¹ for MPhU and 152 kJ mol⁻¹ for 1,3-DPhU, where the estimated errors are comprised within 6 kJ mol⁻¹Enthalpies and temperatures of fusion have been measured by differential scanning calorimetry, leading to 23.7 kJ mol⁻¹ and 420.6 K for MPhU, and 34.6 kJ mol⁻¹ and 512 K for 1,3-DPhU. Poor reproducibility of results for 1,3-DPhU seems be due to the beginning of decomposition. No solid-to-solid transitions have been revealed from r.t. to fusion for both compounds.     

Azoles and azines. 62. Structure of 2-aryl-1,3-oxazine-4,6-diones

¹H,¹³C NMR, IR, and UV spectra have been studied for solutions of a number of potentially tautomeric 2-aryl-1,3-oxazine-4,6-diones and their 5-methyl substituted analogs with variation of substituent at the para position of the benzene ring, as well as compounds with a fixed structure that simulates possible tautomeric forms. The data have been compared with the results of quantum chemical calculations carried out in SSO MO LCAO approximation by the CNO, CNDO/2, and MPNDO/3 methods. In DMSO and THF solution the test compounds exist predominantly as 2-aryl-4-hydroxy-6H-1,3-oxazin-6-ones. The para substituent in the benzene ring does not affect the composition of the tautomer mixture significantly.For Communication 61, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 386–394, March, 1987.     

Stereochemical studies, 88. Saturated heterocycles, 83: Synthesis of stereoisomeric condensed-skeleton 2-imino-substituted 1,3-oxazines

Thiourea ( - , - ) and urea ( - , - ) derivatives have been prepared from - and -2-aminomethyl-1-cyclopentanols, and -l-cyclohexanols and their -methyl derivatives with phenyl isothiocyanate and phenyl isocyanate, respectively. Treatment of and with methyl iodide and then with alkali furnished - with the exception of the - -methyl derivative - 2-phenylimino-1,3-oxazines ( , , - ). The remarkable fact that the ring closure of -2-amino-methyl-1-cyclopentanols gives 1,3-heterocycles with -anellation supports the assumption that the -1,2-disubstituted-1,3-difunctional cyclopentanes undergo ring closure when 1,3-heterocycles with a delocalized pπ bond system are formed. With thionyl chloride the -urea derivatives - afforded an elimination product ( ), whereas the isomers yielded the oxazines by inversion. ¹H and ¹³C NMR spectroscopic studies indicated that in - , the “O-in” conformers are favoured (the methylene group of the hetero ring is , while the oxygen atom is ) and all 3-unsubstituted-2-phenylimino-1,3-oxazines exist exclusively in the tautomeric form with an C=N bond.     

Prins-reaktionen mit arylaldehyden, 1. Mitt.: Arylolefine

Benzaldehyde and substituted benzaldehydes react with styrene (1), -methylstyrene, (E)-1-propenylbenzene and anethole in presence of sulfuric acid to give 2,4,6-triaryl-1,3-dioxanes. In acetic acid from1 and benzaldehyde (1R,3S)-and (1RS,3RS)-1,3-diacetoxy-1,3-diphenylpropane is formed. The relative configuration of the products is determined by means of¹H-NMR spectroscopy.     

Niederkoordinierte Phosphorverbindungen: LVII. Alkali(diphosphaallyl)ferrate,synthese und Reaktionen

Reaction of the diphosphapropene I with Na₂Fe(CO)₄, or treatment of its lithium salt with Fe(CO)₅, affords 1,3-diphosphaallylferrates(− 1). Their condensation with alkyl halides or chlorophosphanes yields either the η²,η¹- or η¹,η¹-1,3-diphosphapropene-iron complexes. Protolysis with hydrogen chloride in ether leads via the hydrido-iron species to a stable 1,3-diphosphapropene-iron compound.     

New monomers and polymers : by Bill M. Culbertson and Charles U. Pittman,Jr., Plenum Press,New York and London, 1984, xi + 494 pages,US$59.50.ISBN 0-306-41477-5.

¹H and ¹³C NMR spectra have shown that the products of the reactions of [RuH(cycloocta-1,5-diene)L₃]⁺ (I, L = PMe₂h) with 1,3-dienes are η³-enyl species and not hydrido(1,3-diene) complexes as inferred previously; similar complexes, with phosphine ligands other than PMe₂Ph, have been prepared.     

Diastereoselective reaction of (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediol with aromatic aldehydes. Synthesis of (1R,2R,4S,5S,8S)-2,8-diaryl-4-(4-nitrophenyl)-1-aza-3,7-dioxabicyclo[3.3.0]octanes

We have synthesized a series of (1R,2R,4S,5S,8S)-2,8-diaryl-4-(4-nitrophenyl)-1-aza-3,7-dioxabicyclo[3.3.0]octanes as a result of reaction of (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediol with aromatic aldehydes. The structure of the compounds obtained was established on the basis of ¹H NMR data. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 757–763, May, 2006.     

Synthesis of 1,3-dihalo-1,3-dioximino-2-propanones

1,3-Dihalo-1,3-dioximino-2-propanones (Hal=Cl or Br), which had been difficult to prepare or unreported, were obtained by the nitrosation of 1,3-dihalo- and 1,3-dihalo-1-oximino-2-propanones by nitrosylsulfuric acid in concentrated H₂SO⁴.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 506–509, February, 1991.     

Synthesis and structure of methyl-substituted 1,3-Dioxa-2-Silacylohexanes

The reaction of dimethyl(diethylthio)silane with 1,3-diols gave methyl-substituted 1,3-dioxa-2-silacyclohexanes.¹H and¹³C NMR spectroscopy were used to study the configuration and predominant conformations of the compounds studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 845–851, June, 1986.     

Heteroadamantanes and their derivatives. 7. Synthesis and mass-spectrometric study of functional derivatives of 5-mono- and 5,7-disubstituted 1,3-diazaadamantanes

The chemical behavior of the carbonyl group of 5-mono and 5,7-disubstituted 6-oxo-1,3-diazaadamantanes was studied. The structures of the functional derivatives obtained were confirmed by IR and ¹H and ¹³C NMR spectral data. The behavior of the compounds under the influence of electron impact was studied, and the principal pathways of fragmentation of their molecules were ascertained.See [1] for Communication 6.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 647–653, May, 1989.     

Saturated nitrogen-containing heterocycles. 18. Catalytic synthesis and formation mechanism of substitutedcis-decahydroquinolines and their isologues

Hydromethylamination of 1,3-diaryl-3-(2-oxocyclohexyl)propan-1-ones produces N-methyl-2,4-diaryldecahydroquinolines with cis-fused hetero- and carbocycles that are stabilized in the A conformation. The reaction involves ^2,3,9,10 intermediates and their subsequent reduction.For No. 17, see [1].N. G. Chernyshevskii, Saratov State University, Saratov 410026, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 929–933, July, 1999.     

Studies in fluorinated 1,3-diketones and related compounds Part XII. Synthesis and spectroscopic studies of some new polyfluorinated 1,3-diketones,and their copper 1,3-diketonates

New polyfluorinated 1,3-diketones have been prepared from polyfluorinated acetophenones and appropriate esters in the presence of sodamide. The corresponding copper 1,3-diketonates have been obtained by treating a methanolic solution of polyfluorinated 1,3-diketone with methanolic solution of copper acetate. The polyfluorinated 1,3-diketones have been characterized by elemental as well as by spectral studies, viz: I.R., ¹H N.M.R. and ¹⁹F N.M.R. In I.R., characteristic absorptions observed are: CF stretching bands (1300 ? 1000) cm^?1, CF deformation modes (900 ? 700 cm^?1) and intramolecular hydrogen bonding (3000 ? 2500 cm^?1). In ¹H N.M.R. methine ( = C$\text{H}$) signal is observed at δ 6.2 ? 6.8 ppm and enolic proton resonance signal at δ 13 ? 15 ppm indicating the presence of strong hydrogen bonding in such polyfluorinated 1,3-diketones.     

Synthesis,structure, and transformation of 1-amino-5-phenyl- 2,6,6-tricyano-3-cyclopropyl-1, 3-cyclohexadiene into 6-phenyl-2-dicyanomethylene-3-cyano-4-cyclopropyl-1, 2-dihydropyridine

1-Amino-5-phenyl-2,6,6-tricyano-3-cyclopropyl-1,3-cyclohexadiene is prepared by reaction of benzylidenemalononitrile with (1-cyclopropylethylidene) malononitrile. According to x-ray structural data, steric effects of the cyclohexadiene cause the C¹-C⁶ and C⁵-C⁶ bond lengths to increase to 1.541(3) and 1.568(3) Å. The weakest bond of the cyclohexadiene, C⁵-C⁶, ruptures homolytically on external energy deposition with subsequent formation of a substituted dihydropyridine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2776–2780, December, 1989.     

Synthesis and conformation of 2-silylethynyl-substituted 2,4,4,6-tetramethyl-1,3-dioxanes

Reaction of 2,4,4,6-tetramethyl-1,3-dioxanium perchlorate with lotsich reagents led to the synthesis of new silylethynyl-substituted 2,4,4,6-tetramethyl-1,3-dioxanes. According to the data of¹H and¹³C NMR and x-ray diffraction analysis, it was established that the 1,3-dioxane ring of the products obtained has the chair conformation.Kuban' State Technological University, Krasnodar 350072, Russia. Ufa State Oil Technical University, Ufa 450062, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 487–493, April, 1998.     

Prins-reaktionen mit arylaldehyden, 1. Mitt.: Arylolefine

Benzaldehyde and substituted benzaldehydes react with styrene (1), -methylstyrene, (E)-1-propenylbenzene and anethole in presence of sulfuric acid to give 2,4,6-triaryl-1,3-dioxanes. In acetic acid from1 and benzaldehyde (1R,3S)-and (1RS,3RS)-1,3-diacetoxy-1,3-diphenylpropane is formed. The relative configuration of the products is determined by means of¹H-NMR spectroscopy.

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Herrn Prof. Dr.Anton v. Wacek, emerit. Vorstand des Instituts für Organische Chemie und Organisch-chemische Technologie der Technischen Universität Graz, in Verbundenheit zum 80. Geburtstag gewidmet.