Stereochemistry of the oxidation and alkylation of trans-1-alkyl-4-ethynyldecahydro-4-quinolols

The stereochemistry of the oxidation and alkylation of the nitrogen atom of trans-1-alkyl-4-ethynyldecahydro-4-quinolols was investigated. The orientation of the substitutents attached to the nitrogen atom in the synthesized N-oxides and quaternary salts was determined on the basis of the PMR spectra and previously obtained data on the stereochemistry of the oxidation of 4-substituted 1,3-dimethyldecahydro-4-quinolols.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 221–224, February, 1977.     

Reaction of alkali-metal hypohalites with stereoisomeric 2-methyl-1-alkyl-2-methyl-4-ethynyldecahydro-4-quinolols

Isomeric 1-alkyl-2-methyl-4- (haloethynyl) decahydro-4-quinolols were synthesized by reaction of the individual stereoisomers of 1-alkyl-2-methyl-4-ethynyl-decahydro-4-quinolols with alkali solutions of potassium hypochlorite and hypobromite. 1-Chloro-2-methyl-4-ethynyl decahydro-4-quinolols are formed by the action of an alkaline solution of potassium hypochlorite on isomeric 2-methyl-4-ethynyldecahydro-4-quinolols. Hydrogenolysis of the carbon-halogen bond accompanied by hydrogenation of the CC bond was observed under conditions of catalytic hydrogenation of 1,2-dimethy1-4-(haloethynyl) decahydro-4-quinolols. Primarily hydrogenolysis of the nitrogen-halogen bond and subsequent reduction of the acetylenic bond occur in the hydrogenation of 1-chloro-2-methyl-4-ethynyldecahydro-4-quinolols. Replacement of chlorine by hydrogen and subsequent alkylation of the resulting secondary amine and formation of the hydrochlorides of the corresponding N-methyl-substituted acetylenic alcohols occur in the reaction of the chloramines with a mixture of formaldehyde and formic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 98–103, January, 1976.     

Investigation of the spatial orientation of the hydroxy group and the intramolecular hydrogen bond in stereoisomeric 2,9-dimethyl- and 1,2,9-trimethyldecahydro-4-quinolols and their 4-ethynyl-substituted derivatives by IR spectroscopy

The spatial orientation of the hydroxy group in stereoisomeric 2,9-dimethyl- and 1,2,9-trimethyldecahydro-4-quinolols and their 4-ethynyl-substituted derivatives was established by IR spectroscopy. The formation of an intramolecular hydrogen bond in the equatorial isomers of trans- and cis-2,9-dimethyl- and 1,2,9-trimethyldecahydro-4-quinolols and cis-2,9-dimethyl- and 1,2,9-trimethyl-4-ethynyldecahydro-4-quinolols, which leads to a small degree of distortion of the chair conformation of the heteroring, was demonstrated. The enthalpy of formation of the hydrogen bond was calculated. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 796–800, June, 1980.     

Reaction of dimethylamines with epimeric (at the 2 and 4 positions) trans-2-methyl- and trans-1,2-dimethyl-4-vinylethynyldecahydro-4-quinolols

A mixture of the corresponding 4-(4-dimethylamino-1,2-butadienyl)- and 4-(4-dimethylamino-1-butynyl)decahydro-4-quinolols, with predominance of the allene components, is formed from each vinylacetylenic alcohol as a result of the addition of diethylamine to epimeric (at the 2 and 4 positions) trans-2-methyl- and trans-1,2-dimethyl-4-vinylethynyldecahydro-4-quinolols. On the basis of the PMR spectra and data on the stabilities of allenic and acetylenic diamino alcohols under the conditions of their formation, it was concluded that the addition of dimethylamine to 4-vinylethynyldecahydro-4-quinolols proceeds simultaneously via two pathways — at the 1,4 and 3,4 positions of the vinylethynyl substituent.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 940–945, July, 1976.The authors thank A. S. Fridman and T. E. Prokof'ev for their participation in the discussion of the PMR spectra.     

1-Methyl-2(3,4)-(1-vinylpyrrol-2-yl)pyridinium iodides: some structural features revealed by 1H and 13C NMR spectroscopy

The reactions of 2-, 3-, and 4-(1-vinylpyrrol-2-yl)pyridines with methyl iodide afford the corresponding quaternary salts. Analysis of their ¹H and ¹³C NMR spectra showed that the quaternization of the nitrogen atom considerably enhances the -acceptor effect of the pyridine ring on the pyrrole ring and on the vinyl group. 1-Methyl-2-(1-vinylpyrrol-2-yl)pyridinium iodide contains no weak intramolecular C--H...N hydrogen bond present in the starting compound.     

Reaction of 2,7-dialkyl- and 1,2.7-trialkyldecahydro-4-quinolones with triethylaluminum

The reaction of triethylaluminum with stereoisomeric 2,7-dimethyl- and 1,2,7-trimethyldecahydro-4-quinolones and their 7-tert-butyl-substituted analogs was studied. The reaction of triethylaluminum with ketones that have an equatorial 2-CH₃ group proceeds in two directions — reduction of the carbonyl group to an alcohol group and alkylation to give tertiary 4-ethyl-substituted alcohols — in benzene. depending on the reagent ratio. The stereochemistry of the reduction of the carbonyl group depends on the temperature. Only an alkylation product is formed in tetrahydrofuran (THF) and diethyl ether. The reaction of triethylaluminum with ketones that have an axial 2-CH₃ group depends on the nature of the solvent. Epimeric secondary alcohols are formed in toluene at various ratios of the reacting substances, whereas tertiary ethyl-substituted alcohols are formed in THF and diethyl ether.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 946–952, July, 1976.     

2-Hetarylimidazoles quaternization

Quaternization of 2-hetarylimidazoles by the action of methyl iodide in anhydrous benzene was performed. The reaction involving 1-methyl-2-pyridyl-1H-imidazoles was studied in detail. Relative rate of 2-hetarylimidazoles quaternization changes in parallel with their basicity. The alkylation of aza group was found to be very sensitive to steric factors. The methylation of 1-methyl-2-(3-pyridyl)-1H- and 1-methyl-2-(4- pyridyl)-1H-imidazoles was accompanied with the formation of isomeric quaternary imidazole and pyridine salts.     

Three-dimensional structures of stereoisomers of 2-phenyl-4-ethynyldecahydro-4-quinolinol

The three-dimensional structures of four stereoisomers of 2-phenyl-4-ethynyldecahydro-4-quinolinol were determined by PMR and IR spectroscopy. The IR spectra of axial alcohols with an axial substituent provide evidence for the existence of two equilibrium forms in solution.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1107–1110, August 1986.     

交联聚4-乙烯基吡啶及其季铵盐负载钯催化剂对丙烯酸甲酯加氢反应的研究

 制备了交联聚4-乙烯基吡啶及碘甲烷,溴乙烷季铵化的聚4-乙烯基吡啶负载钯催化剂,考察了它们催化丙烯酸甲酯加氢反应的性能。对碘甲烷季铵化聚4-乙烯基吡啶负载钯催化剂,其催化加氢活性随载体季铵化程度的增加而减小,并且当载体季铵化程度低于80％时,其催化加氢活性比聚4-乙烯基吡啶负载催化剂高。实验结果表明催化剂制备条件对催化性能有很大影响。     

交联聚4-乙烯基吡啶及其季铵盐负载钯催化剂对丙烯酸甲酯加氢反应的研究

制备了交联聚4-乙烯基吡啶及碘甲烷,溴乙烷季铵化的聚4-乙烯基吡啶负载钯催化剂,考察了它们催化丙烯酸甲酯加氢反应的性能。对碘甲烷季铵化聚4-乙烯基吡啶负载钯催化剂,其催化加氢活性随载体季铵化程度的增加而减小,并且当载体季铵化程度低于80％时,其催化加氢活性比聚4-乙烯基吡啶负载催化剂高。实验结果表明催化剂制备条件对催化性能有很大影响。     

Ionization and appearance potentials in organic chemistry. I—energetic aspects of the mass spectra of stereoisomeric 4-substituted N-alkyl-2-methyldecahydroquinol-4-ols

The ionization potentials for the stereoisomers of trans-fused 1,2-dimethyl- and 1-ethyl-2-methyl-4-R-decahydroquinol-4-ols (R?C?CH, CH?CH₂ or C₂H₅) and the appearance potentials for the [M–CH₃]⁺ and [M–C₂H₅]⁺ ions (loss of 2-CH₃ and 4-C₂H₅ groups potential, respectively) were measured by using the electron impact method. The ionization and appearance potential for [M–CH₃]⁺ are always lower for the isomers with the axial 2-CH₃ group. For the C-2 epimers, the difference between the appearance potentials for the [M–CH₃]⁺ ion values is likely to be equal to the enthalpy differences between the ground states of the epimers and the dissociation energy differences between the axial and equatorial C₂–CH₃ bonds. The appearance potentials for [M–C₂H₅]⁺ for the C-4 epimers possessing the 4-C₂H₅ group were very similar. At the same time, the appearance potentials for the [M–CH₃]⁺ ions were lower for less stable epimers which had an axial 4-C₂H₅ group.     

Conformational analysis of 2-OAryl-2-oxo-4,6-dimethyl- and -4-methyl-1,3,2λ5-dioxaphosphorinanes. Spectroscopic,X-Ray,and solid-state 13C and 31P studies

Results of IR and ¹H, ¹³C, and ³¹P NMR studies of the anancomeric title compounds ( 2–5 ) and compound 1 (Scheme 1) are analyzed to search for the existence of high-energy boat or twist-boat conformations in the equatorial epimers. While the difference in frequencies (Δν)_P=O between the axial and equatorial compounds and ¹³C NMR J_POCC and anti J_POCCH3 values suggest the participation of twist-boat conformations for the equatorial isomers, coupling constants in ¹H NMR J_H4H5a or J_H6H5a and J_H4H5e or J_H6H5e of the equatorial isomers 2e–4e along with the lack of a large ³J_PH in ³¹P NMR are consistent with predominant chair conformations. In addition, an X-ray structure of the equatorial 2-p-nitrophenoxy-2-oxo-cis-4,6-dimethyl-1,3,2-dioxaphosphorinane ( 4e ) showed that the molecule adopts a chair conformation with no severe ring flattening in the OPO region in the solid state. X-ray structures of trans- 4 and trans- 5 displayed chair conformations with mild ring flattening especially in the axial methyl region, presumably as a result of the steric methyl-oxygen interaction. CPMAS ¹³C and ³¹P NMR spectra of 4a and 4e provide evidence against the presence of a significant contribution of a twist-boat conformation in solid equatorial 4e . The NMR spectral analysis of 1e , on the other hand, suggests a substantial contribution of a twist conformation as well as, possibly, some contribution of the inverted chair. © 1997 John Wiley & Sons, Inc. Heteroatom Chem 8: 509–516, 1997     

Unusual hydration of stereoisomeric trans-1, 2-dimethyl-4-vinylethynyldecahydro-4-quinolols

The hydration of stereoisomeric trans-1, 2-dimethyl-4-vinylethynyldecahydro-4-quinolols and their acetates under the conditions of the Kucherov reaction was studied. The reaction proceeds ambiguously; the character of the products depends on the three-dimensional structure of the starting vinylethynyl alcohol or ether. The formation of spirodihydro(tetrahydro) furan and spirotetrahydropyran derivatives of the decahydroquinoline series is characteristic for all of the stereoisomeric vinylethynyldecahydroquinolols. A Favorskii-Nazarov retroreaction, as well as epimerization at the C₂ center of the decahydroquinoline ring, is observed in individual cases during the hydration of the vinylethynyldecahydroquinolols, The hydration of the O-acetates of the vinylethynyldecahydroquinolols proceeds more rapidly and more unambiguously than the hydration of the corresponding alcohols. The structures of the synthesized compounds were proved by a combination of the results of elementary analysis and data from the Raman, IR, PMR, and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1079–1085, August, 1980.     

Reactivity and stereochemical structure of 4-hydroxy- and 4-alkoxyhexahydropyrimidine-2-thiones

Substituted 4-hydroxyhexahydropyrimidine-2-thiones were obtained by the reaction of -isothiocyanatoaldehydes with ammonia or methylamine. When heated with alcohols in the presence of p-toluenesulfonic acids, the synthesized compounds gave the corresponding 4-alkoxyhexahydropyrimidine-2-thiones, which were converted into other 4-alkoxy derivatives by the action of the respective alcohols and were hydrolyzed to the initial 4-hydroxyhexahydropyrimidine-2-thiones by the action of an aqueous solution of oxalic acid or potassium hydroxide. The reaction of the 4-hydroxyhexahydropyrimidine-2-thiones with methyl iodide led to the formation of 2-methylthio-4-hydroxy-3,4,5,6-tetrahydropyrimidine hydriodides. It was shown by PMR spectroscopy that the stereoisomers in which the hydroxyl (or alkoxyl) group has the axial orientation are thermodynamically more stable.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 260–266, February, 1985.     

Crystal and molecular structures of isomeric 2-morpholino-2-thiono-4-methyl-1,3,2-dioxaphosphinane and 2-morpholino-2-oxo-4-methyl-1,3,2-dioxaphosphinane

Two isomeric pairs of compounds, cis- and trans-2-morpholino-2-thiono-4-methyl-1,3,2-dioxaphosphinane ( 1A + 1B ) and 2-morpholino-2-oxo-4-methyl-1,3,2-dioxaphosphinane ( 2A + 2B ) were obtained and separated into the pure compounds by silica gel chromatography. Attempts at crystallization afforded 1A , 1B , and 2B . Each crystalline isomer was studied by the X-ray technique, and each crystal and molecular structures assigned. These studies revealed that 1B and 2B have exocyclic 4-CH₃ and sulfur (for 1B ) or 4-CH₃ and oxygen (for 2B ) in the diequatorial position (cis-geometry), while compound 1A possesses the 4-CH₃ group in equatorial position while sulfur is in an axial position (trans-geometry). For all the examined compounds, all the basic geometrical parameters, such as bond lengths, bond and torsion angles, and the deformation of a chair conformation of the six-membered heterocyclic rings, have been established. Such unambiguous assignment of cis-trans geometry in both pairs of 1 and 2 allowed us to confirm the stereoretentive PS → PO conversion by means of OXONE® and the stereoinvertive mechanism of formic-acid catalyzed hydrolysis of phosphorothiomorpholidates. © 1998 John Wiley & Sons, Inc. Heteroatom Chem 9:271–279, 1998     

Coordination properties of 4(5)-hydroxymethylimidazole and 4(5)-hydroxymethyl-5(4)-methylimidazole towards cobalt(II) ions

Two new complexes of imidazole alcohols, 4-hydroxymethylimidazole (4-CH₂OHim) and 4-hydroxymethyl-5-methylimidazole (4-CH₂OH-5-CH₃im), with cobalt(II) of formula [CoL₂(H₂O)₂](NO₃)₂ were obtained. These compounds were described through single X-ray diffraction studies, spectroscopic (Ir. Far-IR, UV-Vis-NIR) and magnetic measurements. In the present complexes imidazole ligands are bidentate coordinating the heterocyclic ring through pyridine-like nitrogen and the oxygen atom of the hydroxymethyl group (chromophore CoN₂O₄). The shape of Co(II) coordination polyhedra is that of a distorted octahedron, with the equatorial plane defined by the 4-CH₂OHim (or 4-CH₂OH-5-CH₃im) bidentate ligands and two water molecules occupying axial positions (i.e. trans to each other). Formation of successive cobalt(II) complexes with 4-CH₂OH-5-CH₃im in aqueous solution was followed quantitatively by potentiometry.     

Water-soluble 2-aminomethylidene-1,3-dicarbonyl compounds as new chalcogenide colloidal stabilizers

Reactions of 2-ethoxymethylidene derivatives of 1,3-dicarbonyl compounds with N,N-dimethylethane-1,2-diamine gave a number of 2-[(2-dimethylaminoethyl)amino]methylidene-1,3-dicarbonyl compounds which were subjected to regioselective quaternization at the tertiary nitrogen atom with methyl iodide. The resulting quaternary ammonium salts inhibited aggregation of cadmium and zinc sulfide sols in aqueous medium.     

Synthesis and reactions of 2-(4-pyridyl)indole anhydro bases

The corresponding anhydro bases are formed from quaternary salts of 2-(4--pyridyl)indole under the influence of a methanol solution of alkali. The 2-(4-pyridyl)indole cation and 1H-4-(2-indolenylidene)-1,4-dihydropyridine were subjected to quantum-chemical calculation, and the possibility of electrophilic substitution of the anhydro bases in the position of indole was predicted on the basis of the results of the calculations. Thus, the reaction of the anhydro bases with acetyl nitrate and a solution of bromine in acetic acid leads to quaternary salts with a substituent in the position of the indole ring, which are reconverted to anhydro bases under the influence of alkali with retention of the substituent in the position. When the anhydro bases are refluxed in nitromethane and cyanoacetic and malonic esters in the presence of triethylamine, they form the corresponding adducts, which give the starting compounds under the influence of alkali, whereas upon reaction with methyl iodide in ethanol they give quaternary salts. All of these chemical transformations were confirmed by the IR, UV, PMR, and mass spectra.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 52–58, January, 1982.     

Asymmetric synthesis and absolute configuration of 1-α-phenylethyl-2,5-dimethyl-4-piperidone isomers

Reaction of the methyl iodide of trans-1,2,5-trimethyl-4-piperidone with S--phenylethylamine proceeds asymmetrically and leads in 66% optical yield to the formation of the cis- and trans-diastereomeric pair of 1-(-phenylethyl)-2,5-dimethyl-4-piperidone, in which the new asymmetric centers possess the 2S,5S- and 2S,5R-configurations, respectively. According to x-ray structural analysis, the minor trans-1-(-phenylethyl)-2,5-dimethyl-4-piperidone component possesses the 2R,5S-configuration. The occurrence of asymmetric synthesis accompanying transamination was confirmed via the preparation of enantiomers of trans-2,5- and trans-1,2,5-trimethyl-4-piperidones.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1641–1648, December, 1986.     

Stereochemistry of nitrogen heterocycles. 49. Synthesis and transformations of stereoisomeric 4-keto-2-methyl-n-chloro-trans-decahydroquinolines

Epimeric (with respect to the methyl group) stereoisomers of 4-keto-2-methyl-1-chloro-trans-decahydroquinoline were obtained, and their transformations under the influence of triethylamine were investigated. It was shown that the direction of the transformations depends on the steric orientation of the methyl group and the molar ratio of the N-chloroamine and triethylamine. The N-chloroamine isomer with an equatorial methyl group undergoes dehydrochlorination in the presence of excess triethylamine to give 2-methyl-4-hydroxy-trans-5,6,7,8,9,10-hexahydroquinoline. With an equimolar amount of triethylamine in solution in CCl₄ the principal reaction pathway becomes dehydrochlorination and subsequent chlorination to give 2-methyl-4-hydroxy-3-chloro-trans-5,6,7,8,9,10-hexahydroquinoline. The N-chloroamine isomer with an axial methyl group in the presence of both excess and, in particular, equimolar amounts of triethylamine undergoes, in addition to dehydrochlorination and chlorination in the position of the piperidine ring, cis-trans isomerization and subsequent dehydrogenation with the primary formation of 2-methyl-4-hydroxy-3-chloro-5,6,7,8-tetrahydroquinoline. The mechanism of the transformations is examined.See [1] for communication 48.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 792–798, June, 1984