Synthesis of aryl-containing isoprenoids from 1,5-dimethylcycloocta-1,5-diene

A procedure has been developed for the synthesis of Pro-Drone homo analogs from the ozonolysis products of 1,5-dimethylcycloocta-1,5-diene and 1,5-dimethylcyclooctene.     

Ab initio conformational analysis of 1,5‐dithiacyclooctane, 1,5‐diselenacyclooctane,and 1,5‐ditelluracyclooctane

Energy‐minimum structures of 1,5‐dithiacyclooctane (1,5‐DTCO), 1,5‐diselenacyclooctane (1,5‐DSeCO), and 1,5‐ditelluracyclooctane (1,5‐DTeCO) were calculated by the ab initio molecular orbital method. Nine energy‐minimum structures were obtained for each compound. A twist‐boat–chair (TBC) structure is the most stable for 1,5‐DTCO and 1,5‐DSeCO, whereas a boat–boat (BB) structure is the most stable in 1,5‐DTeCO. The TBC conformer of 1,5‐DTCO has received little attention so far. The energy gap between HOMO and NHOMO in the TBC conformer of 1,5‐DTCO is in good agreement with the experimental data (photoelectron spectrum). For 1,5‐DTCO and 1,5‐DSeCO, the boat–chair (BC) conformer in which two chalcogen atoms face each other has the highest HOMO energy among the nine conformers, and the energy barriers between the TBC and BC conformers were calculated to be relatively low for these compounds. Therefore, a conformational change from the TBC to the BC is predicted to occur before these compounds are oxidized in solution. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 159–166, 1999     

Über die Reinheit der käuflichen Farbreagentien 1,5-Diphenylcarbazid und 1,5-Diphenylcarbazon

The commercially available analytical reagents 1,5-diphenylcarbazide and 1,5-diphenylcarbazone were found to contain considerable impurities. In 1,5-diphenylcarbazide an appreciable quantity of 1-phenylsemicarbazide was detected whereas 1,5-diphenylcarbazone was found to contain 1,5-diphenylcarbazide. In most of the reports on the stability and composition of the complexes of these reagents given in literature no consideration was made regarding the possibility of interference from these impurities. — Simple syntheses of pure 1,5-diphenylcarbazide and 1,5-diphenylcarbazone are described here.     

Tautomerism of 1,5-dibenzazolylformazans

The structures of new symmetrical and asymmetrical 1,5-dibenzazolylformazans were investigated by IR and electronic spectroscopy. It is shown that 1,5-dibenzimidazolylformazans, regardless of the substituent in the 3 position (methyl, phenyl), display the presence of the tautomeric imino form in solutions. 1,5-Dibenzothiazolylformazans display a high tendency to form chelate forms. The stability of the chelate increases on passing from the 3-methyl to the 3-phenyl derivative.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 699–701, May, 1973.     

1,5-naphthyridines and their N-oxides

The N-oxidation reactions of 2-hydroxy- and 2-amino-1,5-naphthyridines were investigated. 2-Hydroxy-1,5-naphthyridine 5-oxide and 2-hydroxy-, 2-amino-, and 2-acetamido-1,5-naphthyridine 1,5-dioxides were obtained. The structures of the compounds obtained were proved by means of IR and PMR spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1237–1240, September, 1972.     

Adsorption equilibria in 1,5-diphenyl-3-selenapentane-1,5-dione-solvent-sorbent systems

Adsorption of DAFS-25 (1,5-diphenyl-3-selenapentane-1,5-dione) from dilute solutions in various solvents on various adsorbents was studied by UV spectrophotometry. The experimental data were interpreted thermodynamically by the method of excess Gibbs quantities.     

Chemistry of 1,5-diketones: I. Halogenation of aryl-substituted pent-2-ene-1,5-diones,pentane-1,5-diones,and their fused analogs

Halogenation of 3-(4-methoxyphenyl)-1,5-diphenylpent-2-ene-1,5-dione, 3-(4-methoxyphenyl)-1,5-diphenylpentane-1,5-dione, and 2-[1-(4-methoxyphenyl)-3-oxo-3-phenylpropyl)-1,2,3,4-tetrahydroaphthalen-one with bromine, chlorine, and dichloro(phenyl)-λ³-iodane leads to formation of the corresponding monobromo-, dichloro-, or trichloro-substituted 1,5-diketones, depending on the conditions. Halogenation of the aliphatic chain and methoxyphenyl substituent can be accompanied by heterocyclization to give pyrylium salts.     

Photooxygenation of 1,5-thiaselenocane

A direct comparison of photooxygenation at sulfur and selenium centers is reported, and the reactivity of 1,5-thiaselenocane is compared to that of 1,5-dithiacyclooctane.     

Neue 1,5-benzodiazepinderivate

The 1,5-benzodiazepines 1,6 add benzoylphenylketene ( 3 ) across the azomethine bond to produce the 1,3-oxazino[3,2-a]-1,5-benzodiazepines 4,5,7. In 6a azo coupling occurs at the exocyclic methyl group leading to the formation of 10 , while diazo group transfer takes place at the cyclic methylene group to afford 11. The latter compounds react with 3 without loss of the diazo nitrogen, yielding the diazo-oxazinobenzodiazepine 12 ; whereas, by interaction with phenyl isocyanate, the pyrazolo[4,3-b]-1,5-benzodiazepine 14 is formed.     

碳酸二甲酯法合成1，5-二氨基甲酸甲酯的反应机理

应用红外光谱技术研究了在乙酸锌催化作用下1，5-萘二胺与碳酸二甲酯甲氧基羰基化反应机理．结果表明，二水合乙酸锌只有失去两个结晶水变成无水乙酸锌后才能产生催化活性．无水乙酸锌与1，5-萘二胺形成一个新的配位络合物，该配位络合物是一个适宜的亲核试剂，能与碳酸二甲酯进行亲核反应，生成1，5-萘二胺的甲氧基羰基化产物．在无水乙酸锌与1，5-萘二胺形成配位络合物的过程中，无水乙酸锌的结构从双齿型转变成单齿型．     

碳酸二甲酯法合成1,5-萘二氨基甲酸甲酯的反应机理

 应用红外光谱技术研究了在乙酸锌催化作用下1,5-萘二胺与碳酸二甲酯甲氧基羰基化反应机理. 结果表明,二水合乙酸锌只有失去两个结晶水变成无水乙酸锌后才能产生催化活性. 无水乙酸锌与1,5-萘二胺形成一个新的配位络合物,该配位络合物是一个适宜的亲核试剂,能与碳酸二甲酯进行亲核反应,生成1,5-萘二胺的甲氧基羰基化产物. 在无水乙酸锌与1,5-萘二胺形成配位络合物的过程中,无水乙酸锌的结构从双齿型转变成单齿型.     

The first synthesis of 1,5-diazacyclooctan-2-one and differentially protected 1,5-diazacyclooctanes

An efficient, high-yielding synthesis of 1,5-diazacyclooctan-2-one and subsequent elaboration to a differentially protected 1,5-diazacyclooctane is disclosed.     

由1,5-二羟基多羟基烃合成哌啶衍生物

以1,5-二羟基多羟基烃为原料,通过磺酰化转化为活泼的1,5-二磺酸酯,再与不同类型的伯胺化合物反应生成多羟基哌啶衍生物。 探讨了反应温度、反应时间和伯胺类型等条件对成环反应的影响,当反应温度为90~100 ℃、反应时间为18 h时,成环反应的收率达到了74%~94%。     

Vibrational spectra and molecular conformations of 1,5-dichloro- and 1,5-dibromopentanes and 1,6-dichloro-and 1,6-dibromohexanes

The Raman and IR spectra of 1,5-dichloro- and 1,5-dibromopentanes and 1,6-dichloro-and 1,6-dibromohexanes have been measured. The normal coordinates have been calculated for these molecules using a consistent set of force constants and the molecular conformations studied by analysing the spectra with reference to the results of the calculations. In the crystalline solid state, 1,5-dichloropentane assumes the trans-trans-trans-gauche form and 1,5-dibromopentane, 1,6-dichloro- and 1,6-dibromohexanes assume the all-trans form. The normal coordinate treatment with the well-established force field was of great help in determining the whole molecular form of the relatively large chain molecules.     

Halogenation of 1,5-Diketones

Published and experimental data of authors on halogenation of 1,5-diketones from acyclic (among them chalcogen-containing), semicyclic and bicyclic series resulting in formation of mono-, di-, tri-, and tertahalosubstituted 1,5-dioxo compounds, pyrylium halides, and their fused analogs or aroylfurans are reviewed.     

The configuration and solid state conformation of 3,7-dihydroxy-1,5-bis(p-bromophenyl)octahydro-1,5-diazocine

The crystal structure of 3,7-dihydroxy-1,5-bis(p-brornophenyl)octahydro-1,5-diazocine ( 4 ) has been determined from the three dimensional x-ray diffraction data. This infers a similar structure for 3,7-dihydroxy-1,5-diphenyloetahydro-1,5-diazocine ( 1 ). The molecules are in a twist crown conformation and the configuration of the hydroxyl groups on the 3,7-positions is cis.     

Reactions of 1,5-diketones

Two-ring 1,5-diketones of the benzylidenedicyclohexanone type are capable of existing in equilibrium with 4a-hydroxy-1,2,3,4,4a,5,6,7,8,9a-decahydroxanthenes, the position of which depends on the structure of the 1,5-diketone.     

Syntheses of 1,5-dideoxy-1,5-imino-D-mannitol from D-mannose and from D-glucose

Unambiguous enantiospecific syntheses of 1,5-dideoxy-1,5-imino-D-mannitol (LU1, 1-deoxy-mannojirimycin) are reported (i) from D-mannose via hydrogenation of a 5-azido-5-deoxy mannose, and (ii) from D-glucose, in which the key step involves nucleophilic substitution of a trifluoromethanesulphonyl group from C-2 of D-glucose.     

1,5-Naphthyridines and their N-oxides

The oxidation of 2-methyl-1,5-naphthyridine and its di-N-oxide has yielded 1,5-naphthyridine-1-carboxylic acid and its di-N-oxide, and the di-N-oxide of 1,5-naphthyridine-2-carbaldehyde, some derivatives of which have been obtained.For Communication I, see [1],Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1279–1281, September, 1973.     

Reaction of 1,5-Diphenyl-1,4-pentadien-3-one and 1,5-Diphenyl- 1-penten-4-yn-3-one with Monosubstituted Hydrazines

Phenyl- and isopropylhydrazines react with 1,5-diphenyl-1,4-pentadien-3-one to give 4,5,6,7-tetrahydroindazole derivatives instead of the expected 4,5-dihydropyrazoles. The reaction of phenylhydrazine with 1,5-diphenyl-1-penten-4-yn-3-one leads to formation of 1,5-diphenyl-3-phenylethynyl-4,5-dihydropyrazole. 2,4-Dinitrophenylhydrazine reacts with 1,5-diphenyl-1-penten-4-yn-3-one, affording the corresponding unsaturated hydrazone rather than pyrazole derivative.