Fused Ring Compounds Research Articles

Novel Syntheses of Eight-Membered-Five-Membered Fused-Ring Compounds from Zirconacyclopentadienes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNovel Syntheses of Eight-Membered-Five-Membered Fused-Ring Compounds from ZirconacyclopentadienesTamotsu Takahashi, Martin Kotora, Kayoko Kasai, Noriyuki Suzuki, and Kiyohiko NakajimaCite this: Organometallics 1994, 13, 11, 4183–4185Publication Date (Print):November 1, 1994Publication History Published online1 May 2002Published inissue 1 November 1994https://doi.org/10.1021/om00023a021RIGHTS & PERMISSIONSArticle Views511Altmetric-Citations68LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (348 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Three isomers of tricyclo[10.3.0.04,9]pentadecane-2,10-dione, (I), (II) and (III), and cis-cisoid-cis-9-hydroxy-9-methyltricyclo[9.3.0.03,7]tetradecan-2-one, (IV)

The crystal structures of the four title compounds, which were obtained during studies of the preparation and reactions of 6-8-5 and 5-8-5 fused-ring compounds, have been determined by X-ray diffraction. (I), (II) and (III) are cis-cisoid-cis, trans-cisoid-cis and trans-transoid-cis isomers of the 6-8-5 fused-ring compound, respectively. The eight-membered ring takes a boat-chair form in compounds (I) to (IV)

Studies on 5-8 Fused Ring Compounds. VII. The Conformations of the Eight-Membered Rings in C6–C8–C5 Fused Ring Compounds

Abstract The five cis/trans isomers of C6–C8–C5 fused ring compound, tricyclo[9.4.0.04,8]pentadecane-2,9-dione were synthesized by photocycloaddition of decalin-1,3-dione to cyclopentene. The conformational analyses were carried out by MM2 and the results were compared with X-ray analyses. The eight-membered rings take predominantly boat-chair forms although those in C5–C8–C5 fused ring compounds exist in various conformations.

ChemInform Abstract: 5‐8 Fused Ring Compounds. Part 6. Synthesis of Tricyclo(9.3.0.03,7) tetradec‐3‐ene‐5,10‐dione and Related Compounds.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Ionic iodocarbocyclization reactions of 4-alkenyl- and 4-alkynylmalonate derivatives

The cyclization reactions of dimethyl 4-alkenylmalonate derivatives 1a-d in the presence of I 2 and Ti(Ot-Bu) 4 proceed in a highly regio- and stereocontrolled manner (5-exo cyclization and trans addition) to give (iodoallyl)cyclopentane derivatives 2 or bicyclic lactones 3 through the displacement of the iodide of 2 by an ester group. Iodocarbocyclization reactions of dimethyl [(cycloallenyl)allyl]malonates 1g-i or dimethyl [(methylenecycloalkyl)alkyl] malonates 1j and 1k proceed regio- and stereoselectively to give fused ring compounds or spiro compounds, respectively, as single isomers

Tricyclo[9.3.0.03,7]tetradec-3-ene-5,10-dione (I), tetracyclo[9.3.0.01,5.05,9]tetradecane-2,7-dione (II) and cis-cisoid-cis-2,9-epoxy-9-methyltricyclo[9.3.0.04,8]tetradecan-2-ol (III)

The crystal structures of the three title compounds, which were obtained during studies of the preparation and reactions of 5-8-5 fused-ring compounds, have been determined by X-ray diffraction.

Studies on 5-8 Fused Ring Compounds. VI. Synthesis of Tricyclo[9.3.0.03,7]tetradec-3-ene-5,10-dione and Related Compounds

Abstract The C5–C8–C5 fused ring compounds (the title compound, 11) constituting the carbon skeletal ring of ophiobolane sesterterpenes have been synthesized from one of the photoadducts, 1-acetoxytricyclo[5.4.0.02,6] undecan-8-one (4a) of cyclopentene and 3-acetoxy-2-cyclohexen-1-one. The photoadduct 4a was converted via bromination and retro-aldol cleavage into 5-bromobicyclo[6.3.0]undecane-2,6-dione (8). The allylation of 8 with allyltributyltin and oxidation of the allyl group with palladium(II) chloride-copper(I) chloride yielded 5-acetonylbicyclo[6.3.0]undecane-2,6-dione (10a). Under basic conditions, the intramolecular cyclization of 10a afforded the title compound 11, and was accompanied by tetracyclo[9.3.01,5.05,8]tetradecane-2,7-dione (12). Under acidic conditions, 10a cyclized to 2-methyl-4,5,6a,7,8,9,9a,10-octahydro-6H-cyclopenta[6,7]cycloocta[1,2-b]furan-6-one (13). The structures of 8, 11, 12, and 13 were determined by X-ray analyses.

ChemInform Abstract: 5‐8 Fused Ring Compounds. Part 5. The Conformations of Eight‐Membered Rings in 5‐8‐5 Fused Ring Compounds and Their cis‐trans Isomerization.

AbstractThe photocycloadduct (I) of appropriate bicyclononanedione to cyclopentene undergoes isomerization under basic conditions to give (II) ( P21/n, Z=2) and (III) (P21/a, Z=4).

Studies on 5-8 Fused Ring Compounds. V. The Conformations of Eight-Membered Rings in 5-8-5 Fused Ring Compounds and Their cis-trans Isomerization

Abstract The 5-8-5 fused ring compounds, synthesized by photocycloaddition, cis-cisoid-cis- and cis-transoid-cis-tricyclo[9.3.0.04,8]tetradecane-2,9-dione (1-A and 2-A) and cis-cisoid-cis-tricyclo[9.3.0.03,7]tetradecane-2,9-dione (3-A) were isomerized to trans isomers (1-B, 1-C, 2-B, 2-C, and 3-B) at ring junction under basic conditions. Their molecular structures except for 1-B were determined by X-ray crystallography. The eight-membered rings of these 5-8-5 fused ring compounds were found in various conformations, boat-chair, twist-boat (S4), chair, twist-boat-chair, and chair-chair forms. With regard to the conformations of their eight-membered rings the strain energies were calculated by MM2 and the predicted conformations were compared with those obtained by X-ray crystallography.

Computer design of potentially bioactive molecules by geometric searching with ALADDIN

Structurally novel potential dopamine agonists were designed by searching databases of 3D structures to find templates that match geometric criteria and can be modified into molecules suggested for synthesis. A search of 54,296 3D structures from three different databases generated 499 structurally unique molecules that meet our geometric criteria for D-2 dopaminergic activity. The search identified 8 of 9 classes of known fused ring phenolic dopaminergic compounds and 62 other classes of fused ring compounds with potential activity. The low observed frequency of finding the same ring class more than once suggests that additional searches will design many additional molecules. Compound design based on 3D substructure searching methods appears to be equally applicable to suggesting new classes of compounds for beginning or for mature medicinal chemistry investigations and does not require the construction of special libraries of templates.

ChemInform Abstract: Studies on 5‐8 Fused Ring Compounds. Part 4. The Syntheses of 5‐8‐5 Fused Ring Compounds and the Conformations of Their Eight‐Membered Rings.

ChemInform Abstract: Studies on 5‐8 Fused Ring Compounds. Part 4. The Syntheses of 5‐8‐5 Fused Ring Compounds and the Conformations of Their Eight‐Membered Rings.

Studies on 5-8 Fused Ring Compounds. IV. The Syntheses of 5-8-5 Fused Ring Compounds and the Conformations of Their Eight-Membered Rings

Abstract The isomers, cis-cisoid-cis- and cis-transoid-cis-tricyclo[9.3.0.04,8]tetradecane-2,9-dione (2 and 3) and cis-cisoid-cis-tricyclo[9.3.0.03,7]tetradecane-2,9-dione (4) were synthesized by the photocycloaddition of bicyclo[4.3.0]nonane-2,4-dione (1) to cyclopentene. X-Ray analyses of those compounds revealed that the conformations of the eight-membered rings are twist-boat in 2, chair in 3, and boat–chair form in 4.

Products of non-flaming combustion of phenol-formaldehyde resin foam

Phenol-formaldehyde foam was decomposed by non-flaming combustion under temperature and atmosphere conditions simulating the main stages of a fire development and the decomposition products were studied. The type and amounts of the products were affected by the decomposition conditions. The residue yield, which was large, decreased with increase in temperature and atmospheric oxygen. Volatile products consisted mostly of light gases with some volatile-condensable products. The volatile products included light hydrocarbons, formaldehyde, phenols, aldehydes, ketones, ethers, oxygen-containing heterocycles, fused ring compounds and benzene and its homologues. The concentration dependence on combustion conditions was studied.

The mechanism of orientation of acridine in oriented polyethylene

Spectroscopic and thermal analytical techniques have been used to study the system polyethylene-acridine at solute concentrations of up to a few percent. All data are consistent with the epitaxial growth of acridine microcrystals on the surfaces of the crystalline microfibrils of oriented polyethylene. Acridine microcrystals could not be detected in an unoriented polymer suggesting that the critical lattice match needed for epitaxial growth occurs only when the (110) planes of polyethylene are exposed due to slip during mechanical deformation. Polyethylene is known to crystallize epitaxially on crystals of anthracene and other fused ring compounds providing corroboration of the basic mechanism. It is suggested that specific adsorption related to the mechanism of epitaxial growth of microcrystals may be the major orienting mechanism for, at least, symmetrical fused ring compounds.

Reaction of 2-methyl-1,4-naphthoquinone and its 3-substituted derivatives with active methylene group anions and with diazo compounds

The reaction of 2-chloro-3-methyl-1,4-naphthoquinone (3) with the anion of ethyl cyanoacetate led to a mixture of two epimeric fused-ring cyclopropane compounds, characterised as exo- and endo-1-cyano-1 -ethoxycarbonyl-1a-methyl-1a,7a-dihydro-1H-cyclopropa[b]naphthalene-2,7-dione (8) and (9). Various hydrolysis products of these were prepared and an X-ray crystallographic analysis was carried out on one of them, 1-carbamoyl-1 -carboxy-1a-methyl-1a,7a-dihydro-1H-cyclopropa[b]-naphthalene-2,7-dione (17). The reaction of 2-methyl-1,4-naphthoquinone (1) with ethyl diazoacetate gave a fused pyrazoline derivative, 3-ethoxycarbonyl-4-hydroxy-9a-methyl-1,9a-dihydro-benz[f]indazol-9-one (22), while reaction of 2-methyl-3-nitro-1,4-naphthoquinone (5) with diazomethane led to a fused Δ2-isoxazoline N-oxide, 3a-methyl-3,3a-dihydroisoxazolo[3,4-b]naphthalene-4,9-dione 1-oxide (26).

ChemInform Abstract: SYNTHESIS AND BIOLOGICAL ACTIVITY OF PYRIDAZINOOXAZINES

AbstractAuf dem im Formelschema angegebenen Weg werden aus den Dichlorpyridazinonen (I) die Pyridazinooxazine (IV) hergestellt.

Synthesis and biological activity of pyridazinooxazines.

4-Chloro-5-(2-hydroxyethylamino)-3 (2H)-pyridazinones were converted upon treatment with base to novel fused ring compounds, 3, 4-dihydro-2H-pyridazino [4, 5-b]-1, 4-oxazin-8 (7H)-ones. When a nitrogen atom in the hydroxyethylamino group or at the 2-position of the 3 (2H)-pyridazinone ring had a remaining hydrogen, the ring closure reaction did not occur. 3, 4-Dihydro-2H-pyridazino [4, 5-b]-1, 4-oxazine was similarly synthesized from corresponding precursor. The presence of a C-6 amino group in the precursor did not affect the ring formation mentioned above, but when the amino group was diazotized, ring formation took place in a different fashion, involving the C-6 diazonium moiety as a leaving group, to give another ring system, 6, 7-dihydro-2H-pyridazino [3, 4-b]-[1, 4] oxazin-3 (5H)-one. Similar phenomena were observed in the cases of precursors having a C-6 nitro group : cyclization occurred involving the elimination of the nitro group to give fused ring products. The method was applied to the formation of a tricyclic heterocycle, 2H-pyridazino [3, 4-b] [1, 4] benzoxazin-3 (5H)-one. Some compounds thus obtained were found to have potent analgesic and significant anti-inflammatory activities in animal models.

Organic Content of Particulate Matter In Turbine Engine Exhaust

Solid particulate matter, mainly carbon, emitted into the air from the combustion of fossil fuels contains a variety of organic species adsorbed on it. In our examination of these particulates from the combustion of kerosene type fuels in a gas turbine engine, attention was focused on polynuclear aromatic compounds, phenols, nitrosamines, and total organics. Polynuclears were determined by HPLC, GC/MS, and NMR examination. Phenols and nitrosamines were isolated and then measured by gas chromatography using a flame ionization detector and nitrogen detector. Total organics were determined by a backflush chromatographic procedure. The particulates were collected using a high capacity pumping system and 293 mm diameter teflon filters through which was passed up to 43 m3 of exhaust gas. Extraction of the organic matter was done in a Soxhlet extractor using hexane usually. The engine was operated at idle, approach, climb, and takeoff power settings with low sulfur and high sulfur (0.25%) fuels. Most of the PAH were small 3 and 4 fused ring compounds with very few, at low concentrations, of 5 and 6 fused ring species. No nitrosamines were found and except in a few cases, at low levels, no phenols. PNA and total organic levels decreased with increase in a power setting and were higher in the exhaust from low sulfur fuels. Less than 1% of the organic matter emitted by the engine was absorbed on the particulate matter. The body of information presented in the paper is directed to individuals concerned with the nature of emissions from gas turbine engines. The work was supported by a contract with the Environmental Protection Agency.

Studies on 5–8 Fused Ring Compounds. II. The Crystal and Molecular Structure of 7-Bromo-4,4-dimethylbicyclo[6.3.0]undecane-2,6-dione

Abstract The crystal structure of 7-bromo-4,4-dimethylbicyclo[6.3.0]undecane-2,6-dione has been determined in order to elucidate the configuration and the conformation of 4,4-dimethylbicyclo[6.3.0]undecane-2,6-dione. The crystals of this compound are triclinic with space group P\barl and the unit cell dimensions are, a=7.178, b=16.934, c=6.091 Å, α=96.22, β=100.91, γ=115.39°, and Z=2. The crystal structure was solved by the heavy-atom method and refined by the block-diagonal least-squares method. The final R value for 1473 non-zero reflexions was 0.067. The ring fusion of this compound is trans and the 8-membered ring has a boat-chair conformation.

Studies on 5–8 Fused Ring Compounds. III. Hydrogenolysis of 4,4-Dimethyltricyclo[6.3.0.01,7]undecane-2,6-dione

Abstract Hydrogenolysis of 4,4-dimethyltricyclo[6.3.0.01,7]undecane-2,6-dione with a Pd-C catalyst gave cis-4,4-dimethylbicyclo[6.3.0]undecane-2,6-dione and 8,8-dimethylspiro[4.6]undecane-6,10-dione. The cis isomer has been shown to isomerize almost completely to the trans isomer under acidic and basic conditions.