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Journal articles on the topic 'Bicyclo [5. 3. 1] undécèn-3 dione-2,6'

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Published: 4 June 2021

Last updated: 14 February 2022

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1

Werstiuk, N. H., S. Yeroushalmi, and Hong Guan-Lin. "Synthesis of bicyclic diones and thiones. Facile methylation of the enolates of bicyclo[2.2.1]heptane-2,5-dione and bicyclo[2.2.2]octane-2,5-dione. An AM1 computational study of bicyclic enolates." Canadian Journal of Chemistry 70, no. 3 (1992): 974–80. http://dx.doi.org/10.1139/v92-130.

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A group of bicyclic ketones and thiones have been synthesized for homenolization studies. Bicyclo[2.2.1]heptane-2,5-dione (6) undergoes unusually rapid tetramethylation giving 3,3,6,6-tetramethylbicyclo[2.2.1]heptane-2,5-dione (1) in good yield. Treatment of 1 with P2S5 in xylene gave 3,3,6,6-tetramethylbicyclo[2.2.1]heptane-2,5-dithione (2) and 3,3,6,6-tetramethyl 15-oxo-bicyclo[2.2.1]heptane-2-thione (3), which was converted into 4 with Raney nickel. Bicyclo[2,2,2]octane-2,5-dione (7), prepared via a Diels–Alder reaction between 2-trimethylsilyloxy-1,3-cyclohexadiene and and α-acetoxyacrylon

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2

Hřebabecký, Hubert, Milena Masojídková, Martin Dračínský, and Antonín Holý. "Synthesis of Novel Conformationally Locked Carbocyclic Nucleosides Derived from 3-(Hydroxymethyl)bicyclo[2.2.1]heptane-2,5-diol." Collection of Czechoslovak Chemical Communications 71, no. 6 (2006): 871–88. http://dx.doi.org/10.1135/cccc20060871.

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(1R*,2R*,3R*,4R*,5R*,6S*)-3-Amino-5-(benzyloxy)-6-(hydroxymethyl)bicyclo[2.2.1]heptan-2-ol (18) was prepared in seven easy steps from benzyl (1R*,2S*,3S*,4S*)-3-(benzyloxy)bicyclo[2.2.1]hept-5-ene-2-carboxylate (10). Reaction of amine18with ethylN-((2E)-3-ethoxymethacryloyl)carbamate afforded 1-[(1R*,2R*,3R*,4R*,5S*,6R*)-6-(benzyloxy)-3-hydroxy-5- (hydroxymethyl)bicyclo[2.2.1]heptan-2-yl]-5-methylpyrimidine-2,4(1H,3H)-dione (21) and after deprotection by transfer hydrogenation, free thymine analogue22. The thymine derivative21was converted to 2,3'-anhydronucleoside26. Treatment of the benzyl d

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3

Kurzer, Frederick, and Jane E. Hawkes. "Bicyclo[2.2.2]octane-2-spirocyclohexanes, Part 5 [1] The Action of Grignard Reagents on Spirodiisophora-3′,6-dione." Zeitschrift für Naturforschung B 47, no. 7 (1992): 1000–1006. http://dx.doi.org/10.1515/znb-1992-0718.

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Grignard reagents react with spirodiisophora-3′,6-dione exclusively at its 3′-keto-function, yielding 3′-eq-alkyl(or phenyl)-3′-ax-hydroxyspirodiisophor-6-ones. Successive dehydration and monobromination of the methyl homologue yields products, the structural details of which are settled by their 13C NMR spectra.

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4

Chan, Isa Y. H., Mohan M. Bhadbhade, and Roger Bishop. "Threefold helical assembly via hydroxy hydrogen bonds: the 2:1 co-crystal of bicyclo[3.3.0]octane-endo-3,endo-7-diol and bicyclo[3.3.0]octane-endo-3,exo-7-diol." Acta Crystallographica Section E Crystallographic Communications 77, no. 3 (2021): 270–76. http://dx.doi.org/10.1107/s2056989021001730.

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Reduction of bicyclo[3.3.0]octane-3,7-dione yields a mixture of the endo-3,endo-7-diol and endo-3, exo-7-diol (C8H14O2) isomers (5 and 6). These form (5)2·(6) co-crystals in the monoclinic P21/n space group (with Z = 6, Z′ = 1.5) rather than undergoing separation by means of fractional recrystallization or column chromatography. The molecule of 5 occupies a general position, whereas the molecule of 6 is disordered over two orientations across a centre of symmetry with occupancies of 0.463 (2) and 0.037 (2). Individual diol hydroxy groups associate around a pseudo-threefold screw axis by means

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5

Brown, RFC, KJ Coulston, FW Eastwood, ADE Pullin, and AC Staffa. "Argon Matrix Study of the Infrared Spectrum of Butatrienone." Australian Journal of Chemistry 43, no. 3 (1990): 561. http://dx.doi.org/10.1071/ch9900561.

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Butatrienone, H2C=C=C=C=O, was generated by pyrolysis of each of six different precursors in a stream of argon at temperatures in the range 710-880°C, and the pyrolysate-argon mixture was condensed on a Csl plate at c. 10 K. Infrared spectra were obtained between 4000 and 250 cm-1. Two precursors, buta-2,3-dienoic trifluoracetic anhydride (1) and buta-2,3-dienoyl chloride (2), gave pyrolysates showing a spectrum consisting of six strong bands and five weak bands. Four precursors, bicyclo [2.2.1]hept-5′-en-2′-ylideneacetic trifluoracetic anhydride (3), 5-( bicyclo [2.2.1]hept-5′-en-2′-ylidene)-

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6

Ahlenstiel, Eckart, Wolfgang Kliegel, Steven J. Rettig, and James Trotter. "Structural studies of organoboron compounds. LVII. Synthesis and structure of bicyclic boron-nitrogen betaines. 1-Methyl-5-(3-nitrophenyl)-4,6,9-trioxa-1-azonia-5-boratabicyclo[3.3.1]nonane and 3,3,4-trimethyl-1-(3-nitrophenyl)-2,6,7-trioxa-3-azonia-1-boratabicyclo[2.2.2]octane." Canadian Journal of Chemistry 71, no. 2 (1993): 263–71. http://dx.doi.org/10.1139/v93-038.

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The syntheses and structures of the bicyclic boron-nitrogen betaines 1-methyl-5-(3-nitrophenyl)-4,6,9-trioxa-1-azonia-5-boratabicyclo[3.3.1]nonane, 7a, and 3,3,4-trimethyl-1-(3-nitrophenyl)-2,6,7-trioxa-3-azonia-1-boratabicyclo[2.2.2]-octane, 14a, are reported. Crystals of 7a are orthorhombic, a = 20.256(2), b = 37.652(2), c = 6.642(1) Å, Z = 16, space group Fdd2, and those of 14a are orthorhombic, a = 21.402(2), b = 11.334(3), c = 11.248(2) Å, Z = 8, space group Pbca. The structures were solved by direct methods and were refined by full-matrix least-squares procedures to R = 0.038 and 0.045 (

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7

Delamere, C., C. Jakins, and E. Lewars. "Tests for aromaticity applied to the pentalenoquinones A computational study." Canadian Journal of Chemistry 79, no. 10 (2001): 1492–504. http://dx.doi.org/10.1139/v01-164.

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Criteria for aromaticity and antiaromaticity were applied to the four pentalenoquinones, 1,2-, 1,5-, 1,4-, and 1,6-pentalenoquinone, i.e., bicyclo[3.3.0]octa-4,6,8-triene-2,3-dione (7a), bicyclo[3.3.0]octa-3,5,8-triene-2,7-dione (7b), bicyclo[3.3.0]octa-1(5),3,7-triene-2,6-dione (7c), and bicyclo[3.3.0]octa-1(5),3,6-triene-2,8-dione (7d). Geometry optimizations and frequency calculations were done with the pBP/DN* DFT method as implemented in Spartan, and single-point HF/3-21G calculations to obtain Löwdin bond orders (Spartan), as well as HF/6-31G* NICS calculations (Gaussian 98) were also ca

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8

Brunelli, Michela, Marcus A. Neumann, Andrew N. Fitch, and Asiloé J. Mora. "Temperature phase changes in solid bicyclo[3.3.1]nonane-2,6-dione and bicyclo[3.3.1]nonane-3,7-dione from powder X-ray diffraction data." Journal of Applied Crystallography 40, no. 4 (2007): 702–9. http://dx.doi.org/10.1107/s0021889807028087.

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The crystal structures of bicyclo[3.3.1]nonane-2,6-dione and bicyclo[3.3.1]nonane-3,7-dione have been solved by direct methods and by direct-space simulated annealing, respectively, from powder synchrotron X-ray diffraction data. Both compounds have a transition to a face-centred-cubic orientationally disordered phase (phase I) near 363 K, as shown by differential scanning calorimetry and powder diffraction measurements. Phase II of bicyclo[3.3.1]nonane-2,6-dione, which occurs below 363 K, is monoclinic, space groupC2/c, witha= 7.38042 (4),b= 10.38220 (5),c= 9.75092 (5) Å and β = 95.359 (1)° a

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9

Yengoyan, Aleksandr P., Zhermen A. Azaryan, Vergush A. Pivazyan, Emma A. Ghazaryan, Rafael A. Tamazyan, and Armen G. Ayvazyan. "Synthesis and Preliminary Biological Properties Assessment of Novel 2-S-, 4-, 5-Substituted and Bicyclic Derivatives of 6-Methylpyrimidine-4-ol." Letters in Organic Chemistry 17, no. 2 (2020): 149–56. http://dx.doi.org/10.2174/1570178616666190411110415.

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: A series of novel 2-S-, 4-, 5-substituted and bicyclic 6-methylpyrimidine-4-ol derivatives including pyrazole, 1,2,4-triazole and pyridazine moieties in the molecule were synthesized by accessible and efficient methods. Thiopyrazolyl derivatives were obtained from 2-mercapto-6-methylpyrimidin-4-ol. 4-Triazolyl and 4-aminotriazolylpyrimidines were synthesized from the quaternary ammonium salt of pyrimidine and 4-chloro-substituted 2-thiomethyl-6-methylpyrimidine, respectively. The reaction of potassium salt of 1-methyl-6-oxo-1,6-dihydropyridazin-3-ole with ethyl 2-chloro-3-oxobutanoate and su

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10

Tiwari, Pawankumar R., Marina E. John, and Anil V. Karnik. "Synthesis and Antimicrobial Evaluation of Chiral 3, 5-Diaryl-5, 6-dihydrothiazolo[ 2, 3-c][1, 2, 4]triazoles." Letters in Organic Chemistry 16, no. 12 (2019): 978–82. http://dx.doi.org/10.2174/1570178616666190411102818.

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: Disclosed herein is a general approach for the synthesis of chiral thiazolo triazoles 5a-e. An efficient 3-step synthetic strategy has been developed to obtain the fused heterocycles in good yields. The key step involves formation of a secondary carbocation under acidic condition and intramolecular attack of the nitrogen of the 1,2,4-triazolo part leads to the formation of fused bicyclic compound in a regioselective manner. A new chiral center was created during the reaction and Chiral HPLC analyses confirmed the presence of the same and the racemic nature of the synthesized compounds. Their

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11

Liu, Qi Mei, та Wan Xi Peng. "80°С-Based TD-GC/MS Analysis of Chemical Components from Branches of Cinnamomum camphora". Key Engineering Materials 480-481 (червень 2011): 466–71. http://dx.doi.org/10.4028/www.scientific.net/kem.480-481.466.

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The analytical result by 80°С-based TD-GC/MS showed that 65 peaks were obtained from the helium volatiles from the fresh branches of Cinnamomum camphora and 60 chemical compounds were identified. The results showed that the main components were as: 1,3-Benzodioxole, 5-(2-propenyl)- (12.629%), Tricyclo[2.2.1.0(2,6)]heptane, 1,7-dimethyl-7-(4-methyl-3-pentenyl)-, (-)- (10.302%), 3-Cyclohexene-1-methanol, .alpha.,.alpha.4-trimethyl- (9.084%), Bicyclo[2.2.1] heptan-2-one, 1,7,7-trimethyl-, (1R)- (7.406%), Nerolidol (6.695%), Bicyclo[2.2.1]heptane, 2-methyl-3-methylene-2-(4-methyl-3-pentenyl)-, (1S

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12

Liu, Qi Mei, Dang Quan Zhang, Kuan Peng та Wan Xi Peng. "Deep Analysis on Bioindustry Prospects of 40°С Volatiles of Cinnamomum camphora Branches". Key Engineering Materials 480-481 (червень 2011): 266–71. http://dx.doi.org/10.4028/www.scientific.net/kem.480-481.266.

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Cinnamomum camphora has been used to heal some specific diseases in the Chinese Folk for a long time. In order to explore the wide utilization in biomedicine and spicery, the chemical components of helium volatiles from the fresh branches of C. camphora were studied by TD-GC/MS. The analytical result by TD-GC/MS showed that 50 peaks were obtained from the helium volatiles from the fresh branches of C. camphora and 46 chemical compounds representing 99.993% of the total areas were identified. The results showed that the main components were as: Bicyclo[2.2.1]heptan-2-one, 1,7,7-trimethyl-, (1R)

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13

Jiang, Qianling, Sheng-Jung Ou, and Wei Wei. "Why Shared Bikes of Free-Floating Systems Were Parked Out of Order? A Preliminary Study based on Factor Analysis." Sustainability 11, no. 12 (2019): 3287. http://dx.doi.org/10.3390/su11123287.

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Free-floating bicycle-sharing systems are an important component of sustainable transport. China’s bicycle-sharing schemes have experienced ups and downs in the past three years, and there are a lot of related studies, but there are relatively few studies on the causes of disorderly parking of shared bikes. In this study, an open questionnaire is used to widely collect the causes of the disorderly parking of shared bicycles from users. Through factor analysis, six factors and 32 criteria for the causes of disorderly parking are constructed. Factor 1 ‘supervision and management of enterprises’;

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14

Li, Qing, Dang Quan Zhang, Qi Mei Liu та Kuan Peng. "Determination of Bioactive Components of 60°С Volatiles from Cinnamomum camphora Branches by TD-GC/MS". Advanced Materials Research 230-232 (травень 2011): 852–56. http://dx.doi.org/10.4028/www.scientific.net/amr.230-232.852.

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The chemical components of helium volatiles from the fresh branches of Cinnamomum camphora were studied by TD-GC/MS. The analytical result by 60°С-based TD-GC/MS showed that 55 peaks were obtained from the helium volatiles from the fresh branches of Cinnamomum camphora and 53 chemical compounds were identified. The results showed that the main components were as: Bicyclo[2.2.1]heptan-2-one, 1,7,7-trimethyl-, (1R)- (15.4328%), 1,3-Benzodioxole, 5-(2-propenyl)- (14.881%), Tricyclo[2.2.1.0(2,6)]heptane, 1,7-dimethyl-7-(4-methyl-3-pentenyl)-, (-)- (12.694%), p-menth-1-en-8-ol (9.832%), Bicyclo[2.2

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15

Ngamga, Dieudonne, Josephine Bipa, Pearl Lebatha, et al. "Isoquinoline Alkaloids and Homoisoflavonoids from Drimiopsis barteri Bak and D. burkei Bak." Natural Product Communications 3, no. 5 (2008): 1934578X0800300. http://dx.doi.org/10.1177/1934578x0800300518.

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The powdered bulbs and leaves of Drimiopsis barteri yielded two novel isoquinoline alkaloids: 5-hydroxy-7,2′,3′,4′-tetramethoxy{2H-1-}benzopyran [4,3-c]isoquinoline and 6-hydroxy-7,2′,3′,4′-tetramethoxy{2H-1-}benzopyran [4,3-c]isoquinoline, three new scillascillins: 5,7-dihydroxy-2′,3′,4′-trimethoxyspiro-{2H-1-benzopyran-7′-bicyclo [4.2.0]octa[1,3,5]-triene}-4-one, 5-hydroxy-7,2′,3′,4′-tetramethoxyspiro{2H-1-benzopyran-7′-bicyclo [4.2.0]octa[1,3,5]-triene}-4-one and 5,2′,4′-trihydroxy-7,3′-dimethoxyspiro{2H-1-benzopyran-7′-bicyclo [4.2.0]octa[1,3,5]-triene}-4-one, and a tetrahydroxyhomo-isofla

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16

Maas, Gerhard, and Rainer Rahm. "A Proton-Catalyzed Dimerization of a 2-Amino-1,3-diene which Ultimately Yields a 3-Aminobicyclo[4.2.0]octa-2,4-diene." Zeitschrift für Naturforschung B 60, no. 6 (2005): 673–76. http://dx.doi.org/10.1515/znb-2005-0611.

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The 2-pyrrolidino-1,3-dienes (E)-5 and (Z)-5 are obtained by the reaction of lithium di(tertbutyl) cuprate with propyne iminium salt 3. Quantitative Z→E isomerization of 5 takes place within 4 hours at 20 °C. In benzene solution, (E)-5 slowly equilibrates with a [1,5]-H shift to form the 1-amino-1,3-diene derivative 6. In concentrated chloroform solution, however, (E)-5 is transformed into the 3-pyrrolidino-bicyclo[4.2.0]octa-2,4-diene 7 which is identified by X-ray crystal structure analysis. A mechanism for this transformation is proposed.

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17

Köster, Roland, Günter Seidel, Bernd Wrackmeyer, and Roland Boese. "Organosubstituierte 1,6,2,5-Azoniathiasilaboratabicyclo[3.3.0]oct-3-ene - Herstellung und Kristallstruktur / Organosubstituted 1,6,2,5-A zoniathiasilaboratabicyclo[3.3.0]oct-3-enes - Preparation and Crystal Structure." Zeitschrift für Naturforschung B 50, no. 6 (1995): 959–68. http://dx.doi.org/10.1515/znb-1995-0619.

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The heterocycles Et [R3 = Me: A; R3 = C(Me)=CH2: B] react with 2-aminoethanethiol (1) by elimination of MeNH2 to give the monocyclic [R = Me: 3a; R = C(Me)=CH2: 3b] and the thermically more stable bicyclic compounds [R = Me: 4a; R = C(Me)=CH2: 4b], 4a crystallizes in the monoclinic space group P21/c [lattice constants (at 120 K) a = 9.3239(10), b = 8.9225(11), c = 17.3958(23) Å; β = 92.207(9)°] with a folded bicyclic ring system. cis-ClB(Et)C=C(Me)Si(Me2)Cl (C) and Na2-1BEt3 (prepared from 1 and NaHBEt3) form by elimination of MeNH2 preferentially 3a and minor amounts of 4a. A reacts with o-am

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18

Findlay, John A., and Guoqiang Li. "Novel terpenoids from the Sea Hare Aplysia punctata." Canadian Journal of Chemistry 80, no. 12 (2002): 1697–707. http://dx.doi.org/10.1139/v02-189.

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The structures of 23 compounds isolated from the sea hare Aplysia punctata have been determined by spectroscopic means. These include four new diterpenes (14): 1, neopargueroldione, is a tricyclic diterpene featuring a novel octane-1,5-dione A ring; 2 is deacetylparguerol; 3, punctatene acetate, shares the same [2:2:1] bicyclic system as dactylomelol from A. dactylomela; and 4, punctatol, has the same skeleton as laurencianol of algal origin. Diastereomeric sesquiterpenes 5 and 6 are similar to some compounds of algal origin, as is 7, perforatol, which shares the same carbon framework as perf

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19

Dookhun, Veedeeta, and Andrew J. Bennet. "Synthesis and biological evaluation of a bicyclo[4.1.0]heptyl analogue of glucose-1-phosphate." Canadian Journal of Chemistry 82, no. 9 (2004): 1361–64. http://dx.doi.org/10.1139/v04-109.

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The synthesis of a bicyclo[4.1.0]heptyl analogue of glucose-1-phophate, (1R,2R,3S,4S,5S,6S)-3,4,5-trihydroxy-6-(hydroxymethyl)-bicyclo[4.1.0]heptan-2-yl dihydrogen phosphate (5) is reported. The synthetic route chosen started with methyl α-D-glucopyranoside and was accomplished in 11 steps with an overall yield of 3%. Compound 5 was tested as a potential substrate of UTP:α-D-glucose-1-phosphate uridylyltransferase, the enzyme that converts glucose-1-phosphate into UDP-glucose. However, the conformationally restricted glucose-1-phosphate analogue 5 was found to be a weakly binding inhibitor, ra

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20

Werstiuk, Nick Henry, and Jiangong Ma. "An ab initio study on the magnetic susceptibility and magnetically induced current density distribution of the bicyclo[3.2.1]octa-3,6-dien-2-yl anion." Canadian Journal of Chemistry 77, no. 5-6 (1999): 752–59. http://dx.doi.org/10.1139/v99-049.

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The molecular susceptibility and the atomic contributions including the basin and surface components calculated at the RHF/6-31+G(d)//6-31+G(d) level of theory along with vector current densities obtained at the 6-31++G(d,p)//6-31+G(d) and 6-31+G(d)//6-31+G(d) levels are reported for benzene (1) and correlated - the agreement is excellent - with the results obtained by Keith and Bader with the 6-311++G(2d,2p) basis. This validates our similar studies on the bicyclo[3.2.1]octa-3,6-dien-2-yl anion (2) - initially considered to be a bishomoaromatic species - its parent hydrocarbon bicyclo[3.2.1]o

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21

Piers, Edward, and Grace L. Jung. "Preparation and thermal rearrangement of 2-(tert-butyldimethylsiloxy)-5-methyl-6-exo-[(Z)-3-methyl-1-butenyl]- 4 - exo - vinylbicyclo[3.1.0]hex-2-ene. A total synthesis of (±)-sinularene." Canadian Journal of Chemistry 65, no. 7 (1987): 1668–75. http://dx.doi.org/10.1139/v87-279.

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A total synthesis of the marine sesquiterpenoid (±)-sinularene (1) is described. The alcohol 19 was converted via an 8-step sequence into the bicyclic enone 28. Conjugate addition of lithium divinylcuprate to the latter substance afforded mainly the ketone 30, which was transformed into the enol silyl ether 6. Thermolysis (220 °C, 4.5 h) of 6 provided cleanly the bicyclic triene 7, which, in two steps, was converted into the tricyclic olefinic ketone 34. Hydrogenation of 34 and subsequent Wittig olefination of the resultant ketone 4 with methylenetriphenylphosphorane provided (±)-sinularene (1

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22

Liepa, AJ, AJ Liepa, JS Wilkie, et al. "Preparation of Bicyclic Herbicide Precursors by Intramolecular Stork-Danheiser Kinetic Alkylation Reactions of Methyl 1-(Haloalkyl)-3-methoxy-5-oxocyclohex-3-ene-1-carboxylate Derivatives." Australian Journal of Chemistry 45, no. 4 (1992): 759. http://dx.doi.org/10.1071/ch9920759.

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Reductive alkylation of methyl 3,5-dimethoxybenzoate with the dibromoalkane and the bromochloroalkane derivatives (4a-d) and (4e-g) afforded, after acid hydrolysis, the corresponding methyl 1-( haloalkyl )-3-methoxy-5-oxocyclohex-3-ene-1-carboxylate derivatives (6a-g). Reaction of (6a-c) with lithium diisopropylamide afforded methyl 3-methoxy-5-oxobicyclo[4.2.0]oct-3-ene- 1-carboxylate (2a), methyl 5-methoxy-7-oxo-1,2,3,4,7,7a-hexahydro-3aH-indene-3a-carboxylate (2b) and methyl 6-methoxy-8-oxo-1,3,4,5,8,8a-hexahydronaphtha1ene-4a(2 H)- carboxylate (2c), respectively. Compounds (2b) and (2c) we

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23

Browne, NR, RFC Brown, FW Eastwood, and GD Fallon. "The Chemistry of Ethyl 2-Ethoxycarbonyl-5,5-Diphenylpenta-2,3,4-Trienoate, a Potential Precursor of Ph2c=C=C=C=C=O." Australian Journal of Chemistry 40, no. 10 (1987): 1675. http://dx.doi.org/10.1071/ch9871675.

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The title diester , Ph2C=C=C=C( COOEt )2 (2), has been prepared by a Wittig reaction between (2-bromo-3,3-diphenylprop-2-en-1-yl) triphenylphosphonium bromide and diethyl 2-oxopropane-1,3-dioate ( mesoxalic ester). The diester (2) undergoes cyclization reactions in concentrated sulfuric acid to give diethyl 2-(3'-phenyl-1H-inden-1'-y1idene)propane-l,3-dioate (4) and triethyl 3-oxo-3',9-diphenyl-2,3-dihydrospiro[lH-fluorene-1,l'-[1H]indene]-2,2,4-tricarboxylate (6), the structure of which was determined by X-ray crystallography. The title diester (2)adds cyclopentadiene across the 2,3-C=C bond

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24

Kliegel, W., L. Preu, Steven J. Rettig, and James Trotter. "Structural studies of organoboron compounds. XXI. Crystal and molecular structures of 3-(phenylmethylidene)-4-methyl-1-phenyl-2,6,7-trioxa-3-azonia-1-boratabicyclo-[2.2.2]octane and N-(4-nitrophenylmethylidene)-5-methyl-2-phenyl-1,3-dioxa-2-bora-5-cyclohexaneamine N-oxide." Canadian Journal of Chemistry 63, no. 2 (1985): 509–15. http://dx.doi.org/10.1139/v85-083.

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Crystals of 3-(phenylmethylidene)-4-methyl-1-phenyl-2,6,7-trioxa-3-azonia-1-boratabicyclo[2.2.2]octane are orthorhombic, a = 8.0732(7), b = 11.8499(10), c = 31.679(2) Å, Z = 8, space group Pbca, and those of N-(4-nitrophenylmethylidene)-5-methyl-2-phenyl-1,3-dioxa-2-bora-5-cyclohexaneamine N-oxide are monoclinic, a = 6.1873(6), b = 23.206(2), c = 11.3081(11) Å, β = 92.326(5)°, Z = 4, space group P21/n. Both structures were solved by direct methods and were refined by full-matrix least-squares procedures to final R values of 0.041 and 0.036 for 943 and 1679 reflections with I ≥ 3σ(I), respectiv

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25

Kreiter, Cornelius G., Ernst-Christian Koch, Walter Frank та Guido J. Reiß. "Photochemische Reaktionen von Übergangsmetall-Organyl-Komplexen mit Olefinen, XVI [1]: Photochemisch induzierte Cycloadditionen von Diphenylacetylen an Tricarbonyl(η5-2,4-dimethyl-2,4-pentadien-1-yl)mangan / Photochemical Reactions of Transition Metal Organyl Complexes with Olefins, XVI [1]: Photochemically Induced Cycloadditions of Diphenylacetylene to Tricarbonyl(η5-2,4-dimethyl-2,4-pentadien-1-yl)manganese". Zeitschrift für Naturforschung B 51, № 10 (1996): 1473–85. http://dx.doi.org/10.1515/znb-1996-1019.

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Upon UV irradiation in THF at 208 K tricarbonyl(η5-2,4-dimethyl-2,4-pentadien-1-yl)- manganese (1) yields solvent stabilized, very reactive dicarbonyl(η5-2,4-dimethyl-2,4-pentadien-1-yl)(tetrahydrofuran)manganese (2), which reacts in situ with one or two molecules of diphenylacetylene (3) and yields four manganese complexes and 1,3-dimethyl-5,6-diphenyl-bicyclo[3.2.1]oct-2-ene-7-one (5), which were separated by HPL chromatography. In addition to tricarbonyl η5-4,6 -dimethyl-1,2-diphenyl-cyclohepta-2,4-dien-1-yl)manganese (4) formed by [5+2]cycloaddition and successive 1,4-H shift, tricarbonyl{

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26

Sims, CG, BW Skelton, D. Wege, and AH White. "Some Transformations of 1,6,7,7-Tetrachlorobicyclo[4.1.0]heptan-3-one. Crystal and Molecular Structure of 4-(Dichloromethylene)-1-methyl-5,6-dihydro-1h-indazol-7(4H)-one." Australian Journal of Chemistry 44, no. 11 (1991): 1575. http://dx.doi.org/10.1071/ch9911575.

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Treatment of the title tetrachloro ketone with triethylamine generates 6,7,7-trichlorobicyclo-[4.1.0]hept-1(2)-en-3-one (4), which can be trapped by furan to give two cycloadducts. In the absence of trapping agent, compound (4) undergoes a methylenecyclopropane rearrangement to yield 5-chloro-6-( dichloromethylene ) bicyclo [3.1.0]hexan-2-one. The strained enone (4) can also be intercepted by diazomethane, which affords the title indazolone, whose characterization was supported by a single-crystal X-ray study.

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27

Nami, Navabeh, Mehdi Forozani, Vida Khosravimoghadam, and Rahmatallah Taherinasab. "Synthesis and Characterization of Mono- and Bicycle Heterocyclic Derivatives Containing 1, 2,4-Triazole, 1,3,4-Thiadiazine and 1,3-Thiazole Rings." E-Journal of Chemistry 9, no. 1 (2012): 161–66. http://dx.doi.org/10.1155/2012/867637.

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Reaction of tartaric acid with thiocarbohydrazide(2)and thiosemicarbazide(6)afforded 1,2-bis(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)-ethane-1,2-diol(3)and 1,2-bis(5-mercapto-4H-1,2,4-triazol-3-yl)-ethane-1,2-diol(7). Reaction of compounds3and7with DMAD (dimethylacety lendi carboxylate) and DEAD (diethylacetylendicarboxylate) gave 1,2-bis(7-[(z)-methoxycarbonylmethylen]-5,6-dihydro-5H-6-one-[1,2,4] riazolo[3,4-b] [1,3,4] thiadiazin-3-yl)-ethan-1,2-diol(4), 1,2-bis(7-[(z)-ethoxycarbonylmethylen] -5,6-dihydro -5H-6-one-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)-ethan-1,2- diol(5)and 1,2-bis(

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28

Armbruster, Florian, Uwe Klingebiel, and Mathias Noltemeyer. "Von Ketazinen zu 1,2-Diaza-3-phospha-cyclopent-5-enen, -penta-3,5-dienen, 1,5-Diaza-2,6-diphospha-bicyclo[3.3.0]octa-3,7-dien und einem Cyclohexaphosphan / From Ketazines to 1,2-Diaza-3-phospha-cyclopent-5-enes, -penta-3,5-dienes, 1,5-Diaza-2,6-diphospha-bicyclo[3.3.0]octa-3,7-dien, and Cyclohexaphosphane." Zeitschrift für Naturforschung B 61, no. 3 (2006): 225–36. http://dx.doi.org/10.1515/znb-2006-0301.

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Abstract The dilithium salt of di(tert-butyl-methyl)ketazine 1 reacts with the bimolar amount of ClSiMe3 to give the di(tert-butyl-trimethylsilylmethylen)ketazine, 2. In the reaction of lithiated 2 and F2PN(iPr)2 the 1,2-diaza-3-phosphacyclopent-5-ene (3) is formed. The dichlorophosphanes Cl2PC6H5 and Cl2PCMe3 react with 1 in boiling toluene to give the 1,2-diaza-3-phosphacyclopentenes 4 and 5. The oxygen of the air oxidizes 5 to the 1,2-diaza-3-phosphacyclopent-5-ene 6. Equivalent amounts of H2O cleave the ring skeleton of 5, the tert-butyl-methyl-(tert-butyl-(tert-butylphosphino)methylketazi

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29

Armbruster, Florian, Nina Armbruster, Uwe Klingebiel, Mathias Noltemeyer, and Stefan Schmatz. "Cyclisierung von Di(tert-butyl-methyl)ketazin zu 1,2-Diaza-3-bora- und 1,2-Diaza-3-sila-cyclopent-5-enen / Cyclization of Di(tert-butyl-methyl)ketazine to 1,2-Diaza-3-bora- and 1,2-Diaza-3-sila-cyclopent-5-enes." Zeitschrift für Naturforschung B 61, no. 10 (2006): 1261–74. http://dx.doi.org/10.1515/znb-2006-1013.

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The results of quantum chemical calculations on lithium ketazides suggest mainly four isomeric structures with different modes of lithium coordination (A-D). A monolithium ketazide thf-adduct (1) was isolated supporting the results of the quantum chemical calculations. In reactions of the lithiated di(tert-butyl-methyl)ketazine with BCl3 and Cl2BPh, 1,2-aza-azonia-3-borata-cyclopent-5-enes (2, 3) were isolated. Substitution of a chlorine atom of 2 and 3 with t-BuLi leads to the formation of derivatives 4 and 5. HCl elimination from 2 with Et3N gives - via a diazaboracyclopentene (6) - a bicycl

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30

Ondrus, Theodore A., Purushottam R. Pednekar, and Edward E. Knaus. "Some reactions of 1-methyl-1,2-dihydropyridines with organic azides. Synthesis and reactions of 1,2,5,6-tetrahydropyridylidene-2-cyan(sulfon)amides and piperidylidene-2-cyan(sulfon)amides." Canadian Journal of Chemistry 63, no. 9 (1985): 2362–68. http://dx.doi.org/10.1139/v85-391.

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The regiospecific 1,3-dipolar cycloaddition reaction of 1,2-dihydropyridines 2 with organic azides 3 affords 2,7-diazabicyclo[4.1.0]hept-4-enes 4. Treatment of 4a with neutral aluminum oxide opened the aziridine ring to afford the 1,2,5,6-tetrahydropyridylidene-2-cyanamide 5. Catalytic hydrogenation of 4 and 5 using palladium-on-charcoal and hydrogen yielded the 1-methyl-2-piperidylidenes 6. Oxidation of 1-methyl-1,2,5,6-tetrahydropyridylidene-2-cyanamide (5) with alkaline hydrogen peroxide yielded the oxirane 7 arising from epoxidation of the 3,4-olefenic bond, whereas oxidation of the bicycl

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31

Grigor’eva, Larisa N., Alexsei Ya Tikhonov, Konstantin A. Lomanovich, and Dmitrii G. Mazhukin. "Stable Bicyclic Functionalized Nitroxides: The Synthesis of Derivatives of Aza-nortropinone–5-Methyl-3-oxo-6,8-diazabicyclo[3.2.1]-6-octene 8-oxyls." Molecules 26, no. 10 (2021): 3050. http://dx.doi.org/10.3390/molecules26103050.

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In recent decades, bicyclic nitroxyl radicals have caught chemists’ attention as selective catalysts for the oxidation of alcohols and amines and as additives and mediators in directed C-H oxidative transformations. In this regard, the design and development of synthetic approaches to new functional bicyclic nitroxides is a relevant and important issue. It has been reported that imidazo[1,2-b]isoxazoles formed during the condensation of acetylacetone with 2-hydroxyaminooximes having a secondary hydroxyamino group are recyclized under mild basic catalyzed conditions to 8-hydroxy-5-methyl-3-oxo-

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32

Naghiyev, Farid N., Jonathan Cisterna, Ali N. Khalilov, et al. "Crystal Structure and Hirshfeld Surface Analysis of Acetoacetanilide Based Reaction Products." Molecules 25, no. 9 (2020): 2235. http://dx.doi.org/10.3390/molecules25092235.

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We report an unprecedented multicomponent reaction of acetoacetanilide with malononitrile leading to a structurally novel bicyclic product (9) in a high yield. The structure has been confirmed by X-ray crystallography and comparative Hirshfeld surface analysis of 5-cyano-2-hydroxy-2-methyl-N-phenyl-4-(yridine-4-yl)-6-(thiophen-2-yl)-3,4-dihydro-2H-pyran-3-carboxamide 2, 5-cyano-2-hydroxy-2-methyl-6-oxo-N-phenyl-4-(thiophen-2-yl)piperidine-3-carboxamide 4 and 2-(8-amino-7,8a-dicyano-1-imino-4a-methyl-3-oxo-2-phenyl-1,3,4,4a,5,8a-hexahydroisoquinolin-6(2H)-ylidene)-N-phenylacetamide 9.

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33

Werstiuk, Nick Henry, and Jiangong Ma. "Applications and evaluation of IGAIM 13C and 1H chemical shift calculations for unsaturated hydrocarbons and organolithium compounds." Canadian Journal of Chemistry 74, no. 6 (1996): 875–84. http://dx.doi.org/10.1139/v96-096.

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Wave functions obtained at the RHF/6-31+G(d) level of theory were used with the new method IGAIM (individual gauges for atoms in molecules) developed by Keith and Bader to calculate the isotropic 13C and 1H NMR chemical shifts of a group of neutral molecules (bicyclo[3.2.1]octa-2,6-diene (1), bicyclo[3.2.1]oct-6-ene (2), bicyclo[2.2.1]hepta-2,5-diene (3), benzene (4)), carbanions (prop-2-en-1-yl (allyl) (5), bicyclo[3.2.1]octa-3,6-dien-2-yl (8)), and lithium complexes (prop-2-en-1-yllithium (6) and its dimer 7, bicyclo[3.2.1]octa-3,6-dien-2-yllithium (9)). The theoretical isotropic 13C NMR che

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34

Vaughan, Keith, Shasta Lee Moser, Reid Tingley, M. Brad Peori, and Valerio Bertolasi. "Triazene derivatives of (1,x-)diazacycloalkanes. Part VI. 3-({5,5-Dimethyl-3-[2-aryl-1-diazenyl]-1-imidazolidinyl}methyl)-4,4-dimethyl-1-[2-aryl-1-diazenyl]imidazolidines — Synthesis, characterization, and X-ray crystal structure." Canadian Journal of Chemistry 84, no. 10 (2006): 1294–300. http://dx.doi.org/10.1139/v06-091.

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Reaction of a series of diazonium salts with a mixture of formaldehyde and 1,2-diamino-2-methylpropane affords the 3-({5,5-dimethyl-3-[2-aryl-1-diazenyl]-1-imidazolidinyl}methyl)-4,4-dimethyl-1-[2-aryl-1-diazenyl]imidazolidines (1a–1f) in excellent yield. The products have been characterized by IR and NMR spectroscopic analysis, elemental analysis, and X-ray crystallography. The X-ray crystal structure of the p-methoxycarbonyl derivative (1c) establishes without question the connectivity of these novel molecules, which can be described as linear bicyclic oligomers with two imidazolidinyl group

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35

Coll, JC, and AD Wright. "Tropical Marine Algae. I. New Halogenated Monoterpenes From Chondrococcus hornemannii (Rhodophyta, Gigartinales, Rhizophyllidaceae)." Australian Journal of Chemistry 40, no. 11 (1987): 1893. http://dx.doi.org/10.1071/ch9871893.

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Four linear halogenated monoterpenes: (2Z,6E)-1,8-dichloro-3-chloromethyl-7-methylocta- 2,6-diene (1), (E)-1,2-dibromo-3-chloromethylene-7-methyloct-6-ene (2), (Z)-1-chloro-3-chloromethyl-7-methylocta-2,6-diene (3) and (Z)-1,6-dichloro-3-chloromethyl-7-methylocta-2,7- diene (4), and two epimeric bicyclic monoterpenes (2R*,3(8) E,4S*,6R*)-6-bromo-2-chloro-1,4- oxido-3(8)- ochtodene (5) and (2S*,3(8)E,4S*,6R*)-6-bromo-2-chloro-1,4-oxido-3(8)- ochtodene (6) have been isolated from the red alga Chondrococcus hornernannii collected on the Great Barrier Reef, Australia. The structures were assigned

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36

Aguilar, Angelo, Jianfeng Lu, Liu Liu, et al. "Discovery of 4-((3′R,4′S,5′R)-6″-Chloro-4′-(3-chloro-2-fluorophenyl)-1′-ethyl-2″-oxodispiro[cyclohexane-1,2′-pyrrolidine-3′,3″-indoline]-5′-carboxamido)bicyclo[2.2.2]octane-1-carboxylic Acid (AA-115/APG-115): A Potent and Orally Active Murine Double Minute 2 (MDM2) Inhibitor in Clinical Development." Journal of Medicinal Chemistry 60, no. 7 (2017): 2819–39. http://dx.doi.org/10.1021/acs.jmedchem.6b01665.

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37

Ji, Xiufang, Zhiming Li, Quanrui Wang, and Andreas Goeke. "Alkoxide-induced ring opening of bicyclic 2-vinylcyclobutanones: A convenient synthesis of 2-vinyl-substituted 3-cycloalkene-1-carboxylic acid esters." Beilstein Journal of Organic Chemistry 8 (April 26, 2012): 650–57. http://dx.doi.org/10.3762/bjoc.8.72.

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The fused 2-vinyl or 2-phenyl substituted cyclobutanones 4 undergo stereoselective ring openings by the action of alkoxide ions (t-BuO− or MeO−) to produce novel vicinally disubstituted cycloalkene derivatives 5 and 6 in moderate to high yields. The ring cleavage usually occurs with complete regioselectivity. The accessibility of γ,δ-unsaturated ester or acid derivatives makes this transformation a good supplementary method for the well-established Johnson–Claisen rearrangement.

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38

Blanchfield, JT, DJ Brecknell, IM Brereton, MJ Garson, and DD Jones. "Caloundrin B and Funiculatin A: New Polypropionates From Siphonariid Limpets." Australian Journal of Chemistry 47, no. 12 (1994): 2255. http://dx.doi.org/10.1071/ch9942255.

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Two new polypropionates, caloundrin B (11), systematic name (1″R,2R,3″R,4R,5S,5″R,6S,-7″R,8″S,9″S,10″R)-2-(6′-ethyl-3′,5′-dimethyl-4′-oxopyran-2′-yl)-6-(5″-ethyl-7″-hydroxy-8″,9″,10″-trimethyl-2″,4″,6″-trioxatricyclo[3.3.1.13,7]dec-3″-yl)-5-hydroxy-4-methylheptan-3-one, and funiculatin A (12), systematic name (2ξ,1′S,4R,5′S,6′S)-2-(1′-ethyl-4′,6′,8′-trimethyl-2𔈀,9′-dioxabicyclo[3.3.1]nona-3′,7′-dien-3′-yl)-4,6-dimethylnon-6-en-3-one, have been isolated from Siphonaria zelandica and S. funiculata respectively. The structures of the new compounds were deduced by two-dimensional n.m.r. spectrosco

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39

M. El-Abadelah, Mustafa, Salim S. Sabri, Monther A. Khanfar, Wolfgang Voelter, and Cacilia Maichle-Mössmer. "X-Ray Crystal Structure Analysis of Substituted 5-(2,3-Dihydro-7-benzofuryl)- 2-methylpyrazolo[4,3-d]pyrimidin-7-one (iso-Biagra) [1]." Zeitschrift für Naturforschung B 55, no. 11 (2000): 1079–82. http://dx.doi.org/10.1515/znb-2000-1114.

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X-ray crystal structure data for the substituted 5-(2,3-dihydro-7-benzofuryl)-2-methylpyrazolo[ 4,3-d]pyrimidin-7-one (3) reveal that the two bicyclic heteroaryl systems show no coplanarity along their joint C (5) - C (11) axis with an interplanar angle of 9.6°. Nonetheless, the spatial interatomic distance for O(17)-N(6), determined as 2.73 A, allows the formation of a relatively weak intramolecular hydrogen bond between the pyrimidinone N(6)-H and the O(17) lone pair of the dihydrobenzofuryl moiety.

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40

Lohaus, Edith, Claudia Zenger, Wolfhart Rüdiger та Edmund Cmiel. "Natural Inhibitors of Germination and Growth, III New α-Pyrones from Seeds of Rosa canina". Zeitschrift für Naturforschung C 40, № 7-8 (1985): 490–95. http://dx.doi.org/10.1515/znc-1985-7-806.

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Abstract The new α-pyrone derivative II was isolated in crystalline form from extracts of dormant seeds of Rosa canina. It inhibits germination of seeds of Amaranthus caudatus completely, but reversibly, at conc. > 2.5 × 10-5 м . Its chemical structure was elucidated by mass spectrometry, 1H-and 13C-NMR spectroscopy to be 3-methyl-1-oxa-bicyclo (4,1,0) hept-5-en-2-one-4,6-dicarboxylic acid dimethylester (II). It is derived from 3-methyl-2H-pyran-2-one-4,6-dicarboxylic acid by cyclo-propanation with diazomethane. The parent compound which is a natural product of the seeds of Rosa canina was

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41

Deshmukh, Santosh R., and Shankar R. Thopate. "Synthesis of Novel Fused Regioisomeric Oxetane Bicycles via Paternò-Büchi Reaction of L-Ascorbic Acid and Evaluation as Antiproliferative Agents." Current Organic Synthesis 15, no. 7 (2018): 995–1004. http://dx.doi.org/10.2174/1570179415666180808110014.

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Aim and Objective: To develop efficient method for the synthesis of unusual oxetanes bicycle and diversely functionalized oxetane motifs bearing medicinally relevant functional group in new chemical space and evaluation as cytotoxic agents. Materials and Methods: General procedure for the synthesis of 2, 3, 9 and 11: A mixture of L-ascorbic acid derivative 1 or 8 or 10 (10 mmol) and benzophenone (12 mmol) in dry benzene (125 mL) was purged with dry nitrogen for 5 min. The solution was then irradiated for 20-24 h with UV light (125 W, medium-pressure mercury lamp) in an immersion-well photoreac

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42

Itamura, Sumio, Masao Yamada, Shinji Tamura, Toshihiko Matsumoto, and Toshikazu Kurosaki. "Soluble polyimides with polyalicyclic structure. 1. Polyimides from bicyclo[2.2.2]oct-7-ene-2-exo,3-exo,5-exo,6-exo-tetracarboxylic 2,3:5,6-dianhydrides." Macromolecules 26, no. 14 (1993): 3490–93. http://dx.doi.org/10.1021/ma00066a005.

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43

Shi, Qing-Wen, Anastasia Nikolakakis, Françoise Sauriol, Orval Mamer, and Lolita O. Zamir. "Canadensenes: Natural and semi-synthetic analogues." Canadian Journal of Chemistry 81, no. 5 (2003): 406–11. http://dx.doi.org/10.1139/v03-084.

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The first bicyclic taxanes isolated in the needles of the Canadian yew were named canadensene 1 and 5-epi-canadensene 2. Four additional analogues (36), isolated previously in Taxus chinensis and Taxus mairei, and a new natural 5-epi-canadensene analog 7 with a C-20-cinnamoyl group, were characterized for the first time in the needles of Taxus canadensis. A bicyclic derivative 8 with a docetaxel side chain on C-20 was synthesized using 5-epi-canadensene 2 as starting material. The lack of bioactivities of these bicyclic analogues (tubulin polymerization and cytotoxicities against human cancer

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44

Calcul, Laurent, Karen Tenney, Joseline Ratnam, James H. McKerrow, and Phillip Crews. "Structural Variations to the 9-N-Methyladeninium Diterpenoid Hybrid Commonly Isolated from Agelas Sponges." Australian Journal of Chemistry 63, no. 6 (2010): 915. http://dx.doi.org/10.1071/ch10036.

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Four novel 9-N-methyladeninium diterpenoids, agelasine M (3), 2-oxo-agelasine B (4), gelasine A (5), and gelasine B (6) accompanied by the known-agelasine B (1) and F (2) were isolated from the marine sponge Agelas sp. collected in Papua New Guinea. Compounds 3–6 represent higher unsaturated 9-N-methyladeninium bicyclic diterpenoid derivatives including 5 and 6 as unusual norditerpenoid-agelasines. Their structures were elucidated through detailed physical data analyses and comparison with literature properties. All pure compounds were evaluated for inhibitory activity against Trypanosoma bruc

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45

Calcul, Laurent, Karen Tenney, Joseline Ratnam, James H. McKerrow, and Phillip Crews. "Corrigendum to: Structural Variations to the 9-N-Methyladeninium Diterpenoid Hybrid Commonly Isolated from Agelas Sponges." Australian Journal of Chemistry 64, no. 6 (2011): 846. http://dx.doi.org/10.1071/ch10036_co.

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Four novel 9-N-methyladeninium diterpenoids, agelasine M (3), 2-oxo-agelasine B (4), gelasine A (5), and gelasine B (6) accompanied by the known-agelasine B (1) and F (2) were isolated from the marine sponge Agelas sp. collected in Papua New Guinea. Compounds 3?6 represent higher unsaturated 9-N-methyladeninium bicyclic diterpenoid derivatives including 5 and 6 as unusual norditerpenoid-agelasines. Their structures were elucidated through detailed physical data analyses and comparison with literature properties. All pure compounds were evaluated for inhibitory activity against Trypanosoma bruc

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46

Spannenberg, Anke, Marc A. Bach, Torsten Beweries, and Uwe Rosenthal. "Crystal structure of 3,3-bis(tert-butyl-cyclopentadienyl)- bicyclo[3.1.0]hex-3-zircona-1(5)-ene-6-nickela-6,6-bis(triphenylphosphine), (C9H13)2(ZrC4H4)Ni(C18H15P)-." Zeitschrift für Kristallographie - New Crystal Structures 222, no. 3 (2007): 189–91. http://dx.doi.org/10.1524/ncrs.2007.0078.

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47

Dyall, LK, DW Maloney, JJ Harvey, and BE Fulloon. "Oxidative and Thermal Routes to Novel Isoxazolopyridines." Australian Journal of Chemistry 49, no. 7 (1996): 761. http://dx.doi.org/10.1071/ch9960761.

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The novel bicyclic compounds isoxazolo [3,4-b] pyridine (1). 3-phenylisoxazolo [3,4- b] pyridine (2) and 3-phenylisoxazolo[3,4-c]pyridine (3) have been synthesized by oxidative cyclization of the amines 2-aminopyridine-3-carbaldehyde (4), (2-amino-3-pyridyl)phenylmethanone (5) and (3-amino-4-pyridyl)phenylmethanone (6). The oxidant was bis(acetato-O)phenyliodine. 3-Phenylisoxazolo[3,4-c]pyridine (3) was also obtained by thermolysis of 3-azido-4-benzoylpyridine (7). Comparison of the rate of thermolysis of this azide with that of 3-azidopyridine identified a neighbouring group effect (from the

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48

Deslongchamps, Pierre, Jean Lessard, and Yves Nadeau. "The products of hydrolysis of cyclic orthoesters as a function of pH and the theory of stereoelectronic control." Canadian Journal of Chemistry 63, no. 9 (1985): 2485–92. http://dx.doi.org/10.1139/v85-412.

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The acid hydrolysis of cyclic orthoesters 1, 3–6 (R = Me), and 2 (R = Me and Et) as a function of pH was studied. The bicyclic orthoester 5 yields mainly the hydroxy-ester (less than 5% lactone), and this result is essentially independent of pH. For the other orthoesters, the relative percentage of products differs for each case and varies with pH. At pH ≤ 3, the percentage of lactone is always larger than at pH > 3. These results are explained on the basis of the stereoelectronic theory for the cleavage of tetrahedral intermediates.

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49

Auner, Norbert, and Hans-Uwe Steinberger. "Silaheterocyclen, XXXI [1]. Spaltung von 2-Silanorbornenen: Ein einfacher Weg zu Cyclopentenylderivaten von Organochlorsilanen und zu 2-Silanorbornanen / Silaheterocycles, XXXI [1]. Allyl Cleavage of 2-Silanorbornenes: A Facile Synthesis of Cyclopentenyl- Compounds of Organochlorosilanes and of 2-Silanorbornanes." Zeitschrift für Naturforschung B 49, no. 12 (1994): 1743–54. http://dx.doi.org/10.1515/znb-1994-1220.

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The exo/endo[4+2]-cycloadducts of Cl2Si=CHCH2tBu and cyclopentadiene 1 are transformed into the Si-dimethoxy- and chloro-methyl-substituted derivatives 2 and 4. In the case of the 2-silabicyclo[2.2.1] compounds 2 (R1 = R2 = OCH3), 3 (R1 = R2 = CH3) and 4 (R1 = Cl; R2 = CH3) the allyl cleavage with HCl/ether gives the ring opened products 8, 9, and 10 in good yields. The reaction can also be carried out with HBr/ether. In 1 the cleavage of the allyl-silicon bond is disfavoured due to the two chlorine atoms at silicon. Instead HCl adds to the C=C double bond and stereospecifically gives the exo-

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Mosquera, Janeth, Diana C. Parra, Luis Fernando Gomez, Olga Sarmiento, Tom Schmid, and Enrique Jacoby. "An Inside Look at Active Transportation in Bogotá: A Qualitative Study." Journal of Physical Activity and Health 9, no. 6 (2012): 776–85. http://dx.doi.org/10.1123/jpah.9.6.776.

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Abstract:

Background:The health benefits of physical activity are well documented in scientific literature. Bicycling for transportation is a modality of physical activity that people can incorporate easily into their daily lives.Methods:A qualitative study using 11 semi-structured individual interviews and 5 focus groups was conducted among 31 male and 13 female adult residents of Bogotá, Colombia in 2006, to explore barriers and facilitators of bicycle use for transportation purposes. People were selected based on socioeconomic status, age, and gender. Thematic analysis complemented with thematic netw

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