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Journal articles on the topic 'Bicyclo (2. 2. 1) heptene-2(ethylidene-5)'

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Published: 12 July 2021
Last updated: 8 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 (March 1, 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-acetoxyacrylonitrile followed by a one-step desilylation/hydrolysis, also undergoes facile tetramethylation giving 3,3,6,6-tetramethylbicyclo[2.2.2]octane-2,5-dione (5) in good yield. AM1 calculations were carried out on the α-enolates of bicyclo[2.2.1]heptan-2-one, 6, 5-methylidenebicyclo[2.2.1]heptan-2-one, and 4-acetylbicyclo[2.2.1]-heptan-2-one in an attempt to gain information on the source of the enhanced acidity of the C-3 hydrogens of 6 and 7. Keywords: bicyclic ketones, thiones, synthesis.
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2

Nielsen, P., and F. Tarding. "The Metabolic Fate of 5-(bicyclo-3, 2, 1-oct-2-en-2-yl)-5-ethyl Barbituric Acid, (Reposal ®)." Acta Pharmacologica et Toxicologica 26, no. 6 (March 13, 2009): 521–30. http://dx.doi.org/10.1111/j.1600-0773.1968.tb00471.x.

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3

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 (February 1, 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 (Rw = 0.036 and 0.053) for 975 and 1646 reflections with I ≥ 3σ(F2), respectively. The X-ray analyses establish the bicyclo[3.3.1]nonane and bicyclo[2.2.2]octane "cage" structures for 7a and 14a, respectively. Bond lengths involving the tetrahedral boron atom are (N)O—B = 1.519(5), (C)O—B = 1.444(6) and 1.443(6), C(aryl)—B = 1.602(5) Å for 7a; and (N)O—B = 1.530(3), (C)O—B = 1.446(3) and 1.455(3), C(aryl)—B = 1.608(3) Å for 14a. Weak [Formula: see text] interactions are the main feature of the crystal packing arrangements of both compounds.
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4

Gavina, Francisco, Ana M. Costero, Ana M. Gonzalez, and Santiago V. Luis. "Existence and reactivity of bicyclic annulenones. 2. Bicyclo[3.3.0]octa-1(5),3,7-triene-2,6-dione." Journal of Organic Chemistry 52, no. 14 (July 1987): 2997–99. http://dx.doi.org/10.1021/jo00390a009.

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5

Yang, Ying-Qun, Wei Li, Zhi-Min Chen, and Li-Xia Fu. "Crystal Structure and Properties of a New Copper(II) Complex Cu2(phen)2[C7H8(COO)2]2 (H2O)4:5." Zeitschrift für Naturforschung B 67, no. 9 (September 1, 2012): 872–76. http://dx.doi.org/10.5560/znb.2012-0097.

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A new complex Cu2(phen)2[C7H8(COO)2]2 (H2O)4:5 (1) has been synthesized, with the dianion of bicyclo[2.2.1] hept-2-ene-5,6-dicarboxylic acid [C7H8(COOH)2] (LH2) and 1,10-phenanthroline (phen) as ligands. In 1, L2- anions link Cu(II) cations to form two binuclear structure units, in which each Cu(II) cation is coordinated by five donor atoms to give a distorted square-pyramidal geometry. The magnetic data of 1 show that it exhibits weak antiferromagnetic properties at low temperature. When the excitation wavelength is at 470 nm, it has an intense photoluminescence. In addition, the cyclovoltammetric electron transfer is quasi reversible in the electrode reaction of 1, two electrons being involved in the reaction corresponding to Cu(II)=Cu(0)
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6

Akabane-Nakata, Masaaki, Namrata D. Erande, Pawan Kumar, Rohan Degaonkar, Jason A. Gilbert, June Qin, Martha Mendez, et al. "siRNAs containing 2′-fluorinated Northern-methanocarbacyclic (2′-F-NMC) nucleotides: in vitro and in vivo RNAi activity and inability of mitochondrial polymerases to incorporate 2′-F-NMC NTPs." Nucleic Acids Research 49, no. 5 (February 12, 2021): 2435–49. http://dx.doi.org/10.1093/nar/gkab050.

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Abstract We recently reported the synthesis of 2′-fluorinated Northern-methanocarbacyclic (2′-F-NMC) nucleotides, which are based on a bicyclo[3.1.0]hexane scaffold. Here, we analyzed RNAi-mediated gene silencing activity in cell culture and demonstrated that a single incorporation of 2′-F-NMC within the guide or passenger strand of the tri-N-acetylgalactosamine-conjugated siRNA targeting mouse Ttr was generally well tolerated. Exceptions were incorporation of 2′-F-NMC into the guide strand at positions 1 and 2, which resulted in a loss of the in vitro activity. Activity at position 1 was recovered when the guide strand was modified with a 5′ phosphate, suggesting that the 2′-F-NMC is a poor substrate for 5′ kinases. In mice, the 2′-F-NMC-modified siRNAs had comparable RNAi potencies to the parent siRNA. 2′-F-NMC residues in the guide seed region position 7 and at positions 10, 11 and 12 were well tolerated. Surprisingly, when the 5′-phosphate mimic 5′-(E)-vinylphosphonate was attached to the 2′-F-NMC at the position 1 of the guide strand, activity was considerably reduced. The steric constraints of the bicyclic 2′-F-NMC may impair formation of hydrogen-bonding interactions between the vinylphosphonate and the MID domain of Ago2. Molecular modeling studies explain the position- and conformation-dependent RNAi-mediated gene silencing activity of 2′-F-NMC. Finally, the 5′-triphosphate of 2′-F-NMC is not a substrate for mitochondrial RNA and DNA polymerases, indicating that metabolites should not be toxic.
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7

Koch, Ernst-Christian, and Guido J. Reiss. "Photochemisch induzierte C–C-Verknüpfungen zwischen einem Mangan-koordinierten Pentadienylliganden und Acetylen." Zeitschrift für Naturforschung B 70, no. 2 (February 1, 2015): 143–50. http://dx.doi.org/10.1515/znb-2014-0227.

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AbstractIrradiation of tricarbonyl(η5-2,4-dimethyl-2,4-pentadien-1-yl)manganese (1) in tetrahydrofuran (THF) at 208 K affords the carmine solvent complex dicarbonyl(η5-2,4-dimethyl-2,4-pentadien-1-yl)(THF)manganese (2). Complex 2 thermally reacts with acetylene (3) to give tricarbonyl(η3:2-1,3-dimethyl-bicyclo[3.3.1]-3,6-nonadien-2-yl)manganese (4) and dicarbonyl(5-7,10-13-η-6,8-dimethyl-1,3,5,8,10,12-tridecahexaen-5-yl)manganese (5). The crystal structure of complex 4 was determined at room temperature [triclinic space group $P\bar 1,$a=7.6891(9), b=8.3860(8), c=10.5252(13) Å, α=93.000(9)°, β=93.390(10)°, γ= 108.032(8)°, V=642.43(13) Å3]. The manganese atom is trigonal-bipyramidally coordinated by three carbonyl ligands, one ethenylic and one allylic fragment. Consequently, the bicyclic olefin ligand 1,3-dimethyl-bicyclo[3.3.1]-3,6-nonadiene coordinates the manganese atom in a η3:2 mode. The constitution of complex 5 was deduced from IR data, elemental analysis, and 1H NMR spectra. For the formation of complexes 4 and 5, a reaction mechanism is proposed.
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8

Zhang, Dang Quan, Huai Yun Zhang, Lin Lin Guo, and Kuan Peng. "Determination of Bioactive Components of Acetone Extractives of Cinnamomum camphora Root Wood by Py-GC/MS under 350°C." Advanced Materials Research 230-232 (May 2011): 837–41. http://dx.doi.org/10.4028/www.scientific.net/amr.230-232.837.

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Py-GC/MS technology was used to analyze the high-grade resource recovering approaches of C. camphora root wood at 350°C. The result showed that the chemical components of acetone extractives from C. camphora root wood are as: Benzene, 1,2-dimethoxy-4-(2-propenyl)- (10.255%), Bicyclo[2.2.1]heptan-2-one, 1,7,7-trimethyl-, (1R)- (7.751%), p-menth-1-en-8-ol (5.765%), Phenol, 2,6-dimethoxy-4-(2-propenyl)- (3.833%), 1,6-Cyclodecadiene, 1-methyl-5-methylene-8- (1-methylethyl)-, [s-(E,E)]- (3.669%), D-Allose (3.265%), Acetic acid (2.784%), 1(2H)-Naphthalenone, octahydro-8a-hydroxy- (2.719%), 1,3-Benzodioxole, 4-methoxy-6- (2-propenyl)- (2.674%), .beta.(3,4-Methylenedioxyphenyl)propionic acid (2.216%), Phenol, 4-methyl- (2.200%), Phenol, 2,6-dimethoxy- (2.138%), 3,4-Methylenedioxyphenyl acetone (2.125%), 5-Hepten-2-one, 6-methyl- (2.075%), 2-Oxabicyclo[2.2.2]octan-6-ol, 1,3,3-trimethyl- (1.808%), Phenol, 2-methoxy-3-(2-propenyl)- (1.688%), etc. The analytical result by 350°C-based Py-GC/MS showed that the 350°C pyrolyzate of acetone extractives from C. camphora root wood can be used as top value-added materials of biomedicine, but also used as the bioactive materials of bioenergy, cosmetic, food, and other industrial solvents.
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9

Fun, Hoong-Kun, Ching Kheng Quah, Chengmei Huang, and Haitao Yu. "1-Benzyl-5-methoxy-2′,3-dimethyl-4,6-dioxa-2-azaspiro[bicyclo[3.2.0]hept-2-ene-7,4′-isoquinoline]-1′,3′(2′H,4′H)-dione." Acta Crystallographica Section E Structure Reports Online 67, no. 6 (May 7, 2011): o1311—o1312. http://dx.doi.org/10.1107/s160053681101600x.

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10

Bourhis, Mireille, René Golse, Michel Goursolle, and Philippe Picard. "Synthesis of new norbornenones with the aminoester group methyl bicyclo [2-2-1] hept 5-ene 7-one 1-amino 2-carboxylates." Tetrahedron Letters 26, no. 29 (January 1985): 3445–48. http://dx.doi.org/10.1016/s0040-4039(00)98660-x.

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11

Petrov, Viacheslav A. "Stereoselective synthesis of 3-[(perfluoroprop-1-en-2-yl)bicyclo[2.2.1]-hept-5-en-2-yl]sulfanes." Mendeleev Communications 16, no. 3 (January 2006): 155–57. http://dx.doi.org/10.1070/mc2006v016n03abeh002327.

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12

Saito, Nozomi, Yuki Tanaka, and Yoshihiro Sato. "Ruthenium-Catalyzed [2 + 2] Cycloaddition of Allenynes Leading to a Bicyclo[4.2.0]octa-1(8),5-diene Skeleton." Organic Letters 11, no. 18 (September 17, 2009): 4124–26. http://dx.doi.org/10.1021/ol901616b.

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13

Pachuta-Stec, Anna, Urszula Kosikowska, Anna Chodkowska, Monika Pitucha, Anna Malm, and Ewa Jagiełło-Wójtowicz. "Biological Activity of Novel N-Substituted Amides of endo-3- (3-Methylthio-1,2,4-triazol-5-yl)bicyclo[2.2.1]hept-5-ene-2- carboxylic Acid and N-Substituted Amides of 1-(5-Methylthio- 1,2,4-triazol-3-yl)cyclohexane-2-carboxylic Acids." Zeitschrift für Naturforschung C 67, no. 3-4 (April 1, 2012): 123–28. http://dx.doi.org/10.1515/znc-2012-3-403.

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N-Substituted amides of endo-3-(3-methylthio-1,2,4-triazol-5-yl)bicyclo[2.2.1]hept-5-ene- 2-carboxylic acid and 1-(5-methylthio-1,2,4-triazol-3-yl)cyclohexane-2-carboxylic acid were prepared by the condensation reaction of endo-S-methyl-N1-(bicyclo[2.2.1]hept-5-ene-2,3- dicarbonyl)isothiosemicarbazide and S-methyl-N1-(cyclohexane-2,3-dicarbonyl)isothiosemicarbazide with primary amines. The synthesized compounds were screened for their microbiological and pharmacological activities
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14

Stritt, H. P., H. J. Wörz, and H. P. Latscha. "Bildungsmechanismus und Folgereaktionen von 1.2.5.6-Tetraphospha-3.4—7.8-dibenzo-2.6-diiodo-bicycIo[3.3.0]octan Elektrochemische Darstellung von 1.2.5.6-Tetraphospha-3.4—7.8-dibenzo-2.6-dichloro-bicyclo[3.3.0]octan / Formation and Reaction Products of 1.2.5.6-Tetraphospha-3.4—7.8-dibenzo-2.6-diiodo-bicyclo[3.3.0]octane Electrochemical Synthesis of 1.2.5.6-Tetraphospha-3.4—7.8-dibenzo-2.6-diiodo-bicyclo[3.3.0]octane." Zeitschrift für Naturforschung B 40, no. 12 (December 1, 1985): 1711–14. http://dx.doi.org/10.1515/znb-1985-1218.

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Abstract The reaction of o-phenylene-bis(dichlorophosphane) (1) [2] with anhydrous Lil in benzene gives o-phenylene-bis(diiodophosphane) (2). In the presence of water the reaction leads to the bicyclus 3 [1], Electrolysis of 1 with a mercury-pool at a potential of -800 mV in a 1.2-dichloroethane/ 0.1 Mtetrabutylammonium tetrafluoroborate solution gives 1.2.5.6-tetraphospha- 3.4-7.8-dibenzo-2.6-dichloro-bicyclo[3.3.0]octane (4). The reduction of 3, either by magnesium in THF or by electrolysis in 1.2-DCE/0.1 M TBATFB solution at a potential of -1 V yields the oligomer (o-C6H4P2)5
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15

Fun, Hoong-Kun, Ching Kheng Quah, Chengmei Huang, and Haitao Yu. "(1S*,4′S*,5R*)-1-Isopropyl-5-methoxy-2′,3-dimethyl-4,6-dioxa-2-azaspiro[bicyclo[3.2.0]hept-2-ene-7,4′-isoquinoline]-1′,3′(2′H,4′H)-dione." Acta Crystallographica Section E Structure Reports Online 67, no. 5 (April 29, 2011): o1271—o1272. http://dx.doi.org/10.1107/s1600536811015315.

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16

Fun, Hoong-Kun, Ching Kheng Quah, Chengmei Huang, and Haitao Yu. "(1S*,4′S*,5R*)-1-Isobutyl-5-methoxy-2′,3-dimethyl-4,6-dioxa-2-azaspiro[bicyclo[3.2.0]hept-2-ene-7,4′-isoquinoline]-1′,3′(2′H,4′H)-dione." Acta Crystallographica Section E Structure Reports Online 67, no. 5 (April 29, 2011): o1273—o1274. http://dx.doi.org/10.1107/s1600536811015327.

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17

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 (October 9, 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 antimicrobial activities were evaluated by broth micro-dilution method and expressed as the minimum inhibitory concentration. The preliminary bioassay results demonstrate that most of the target compounds exhibit a significantly wide spectrum activity against S. aureus and E. coli comparable to ampicillin. The efficacies of compounds against C. albicans are either more or similar compared to Griseofulvin.
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18

Fun, Hoong-Kun, Ching Kheng Quah, Chengmei Huang, and Haitao Yu. "5-Methoxy-1,2′,3-trimethyl-4,6-dioxa-2-azaspiro[bicyclo[3.2.0]hept-2-ene-7,4′-isoquinoline]-1′,3′(2′H,4′H)-dione." Acta Crystallographica Section E Structure Reports Online 67, no. 6 (May 7, 2011): o1340—o1341. http://dx.doi.org/10.1107/s1600536811016266.

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19

Liu, Qi Mei, and Wan Xi Peng. "80°С-Based TD-GC/MS Analysis of Chemical Components from Branches of Cinnamomum camphora." Key Engineering Materials 480-481 (June 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-exo)- (6.017%), Bicyclo[2.2.1]heptan-2-one, 1,7,7-trimethyl-, (.+/-.)- (4.885%), Bicyclo[3.1.1]hept-2-ene, 2,6-dimethyl-6-(4-methyl-3-pentenyl)- (4.680%), Naphthalene, 1,2,3,5,6,8a-hexahydro-4,7-dimethyl-1-(1-methylethyl)-, (1S-cis)- (4.139%), 3-Cyclohexen-1-ol, 4-methyl-1-(1-methylethyl)-, (R)- (3.538%), Copaene (2.749%), Bicyclo[2.2.1] heptan-2-ol, 1,7,7-trimethyl-, (1S-endo)- (2.643%), Acetic acid, 1,7,7-trimethyl-bicyclo [2.2.1]hept-2-yl ester (2.536%), Cyclohexane, bromo- (2.530%), 1,6,10-Dodecatriene, 7,11- dimethyl-3-methylene-, (E)- (1.725%), Naphthalene, 1,2,3,4,4a,5,6,8a-octahydro-7-methyl-4- methylene-1-(1-methylethyl)-, (1.alpha.,4a.beta.,8a.alpha.)- (1.265%), Bicyclo[4.4.0]dec-1-ene, 2-isopropyl-5-methyl-9-methylene- (1.174%), (-)-Isosativene (1.149%), 11-Tetradecen-1-ol acetate (1.118%), .alpha.-Cadinol (1.061%), etc. The analytical result suggested that the helium volatiles from the fresh branches of C. camphora could be used as industrial materials of biomedicines, spicery and food industry.
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20

Leigh, William J., J. Alberto Postigo, and K. C. Zheng. "Cyclobutene photochemistry. Adiabatic photochemical ring opening of alkylcyclobutenes." Canadian Journal of Chemistry 74, no. 6 (June 1, 1996): 951–64. http://dx.doi.org/10.1139/v96-105.

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The photochemistry of the cis and trans isomers of a series of dimethylbicyclo[n 2.0]alk-(n + 2)-enes (n = 2–5) (bicyclic cyclobutene derivatives in which the C=C bond is shared by the two rings) in pentane solution is described. Irradiation of these compounds using monochromatic 193- or214-nm light sources results in ring opening to yield the corresponding 1,2-bis(1-ethylidene)cycloalkanes (C4–C7) in high chemical and quantum yields. In all cases, the reaction proceeds with a high (70–90%) degree of disrotatory stereoselectivity. Quantum yields for direct cis,trans photoisomerization of the isomeric E,E-and E,Z-1,2-bis(1-ethylidene)cycloalkanes have also been determined. The product distributions from irradiation of the cyclobutenes are wavelength dependent, but for 214-nm excitation the isomeric diene distributions obtained from cyclobutene ring opening agree fairly closely with those calculated from the quantum yields for cis,trans photoisomerization of the isomeric dienes on the assumption that the process involves purely disrotatory ring opening to yield a single diene isomer in the lowest excited singlet state. The results are consistent with an orbital-symmetry-controlled, adiabatic mechanism for ring opening. Key words: photochemistry, cyclobutene, electrocyclic, adiabatic, conical intersection, orbital symmetry.
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21

Pushpanathan, V., and D. Suresh Kumar. "Synthesis and Characterization of Zn Nanoparticles by Using Hetero-Bicyclic Compound." Advanced Materials Research 938 (June 2014): 3–8. http://dx.doi.org/10.4028/www.scientific.net/amr.938.3.

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The 1:1 condensation reaction between benzil and tris (hydroxymethyl) aminomethane in methanol yields a hetero bicyclic compound 5-(hydroxymethyl)-1,2-diphenyl-3,7-dioxa-8-aza-bicyclo [3.2.octan-2-ol. It was characterized by FT-IR, NMR (1H and 13C) spectroscopy and ESI mass spectrometry. The structure was conclusively determined by X-ray diffractrometric analysis. The structure shows a hetero bicyclic ring system. It consists of six membered morpholine and five membered oxazolidine rings with free hydroxyl groups. This bicyclic compound was used as a reducing and stabilizing agent to prepare zinc nanoparticles. The morphology and structure were characterized by field emission scanning electron microscope (FE-SEM), powder X-ray diffraction (XRD), and energy dispersive spectrum analysis (EDS).
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22

Haghdadi, Mina, and Nasim Nab. "A theoretical study on the regio- and stereoselectivity of [3+2] cycloaddition of 2-(trifluoroacetyl)vinyl ethyl ether to 2-arylidene-5-oxopyrazolidin-2-ium-1-ides." Journal of the Serbian Chemical Society 83, no. 3 (2018): 285–303. http://dx.doi.org/10.2298/jsc170511099h.

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[3+2] Cycloaddition reactions of 2-(trifluoroacetyl)vinyl ethyl ether (1) to substituted and unsubstitued 2-arylidene-5-oxopyrazolidin-2-ium-1-ides (2a?e) were studied using density functional theory (DFT) methods at the cc-pVDZ level. The mechanistic details of these reactions, especially with respect to regio- and stereoselectivity, were analyzed. Analysis of the relative energies that are associated with the different reaction pathways indicated that the presence of the trifluoroacetyl group in the dipolarophile and substituents on the aryl ring in the dipolar have a remarkable effect on selectivity. In addition, it was found that the ortho?endo pathway with the lowest activation energy is preferred, which is in good agreement with the experimental data. Moreover, the elimination of ethanol from the [3+2] cycloadducts and the formation of bicyclic pyrazolidinones are explained in order to give a total description of the complete domino processes. The inclusion of solvent effects increased the activation energies and the exothermic character of the cycloadducts, but did not change the gas phase selectivity. The DFT-based reactivity indices clearly predicted the experimental regiochemistry.
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23

Werstiuk, Nick Henry, and Chandra Deo Roy. "Experimental and AM1 calculational studies of the deprotonation of bicyclo[2.2.2]octane-2,5-dione and bicyclo[2.2.2]octane-2,6-dione: a study of homoconjugation, inductive, and steric effects on the rates and diastereoselectivities of α enolization." Canadian Journal of Chemistry 73, no. 3 (March 1, 1995): 460–63. http://dx.doi.org/10.1139/v95-060.

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The kinetics of NaOD-catalyzed H/D exchange (enolization) at C3 α to the carbonyl group of bicyclo[2.2.2]octane-2,5-dione (1) and bicyclo[2.2.2]octane-2,6-dione (2) have been studied in 60:40 (v/v) dioxane–D2O at 25.0 °C. The second-order rate constants for exchange are (9.7 ± 1.5) × 10−1 and (3.4 ± 1.2) × 10−5 L mol−1 s−1 for 1 and 2, respectively. Thus, 1, exchanges 76 times faster than bicyclo[2.2.2]octan-2-one (3) (k = (1.27 ± 0.02) × 10−2 L mol−1 s−1), but the 2,6-dione 2 unexpectedly is much less reactive (2.7 × 10−3) than the monoketone. Unlike the large exo selectivity of 658 observed in the case of bicyclo[2.2.1]heptan-2-one, small and opposite selectivities, exo (1.2) for 1 and endo (2.1) for 2, are found for the isomeric [2.2.2] ketones. The results indicate that the incipient enolate of 1 is stabilized by a polar effect of the β carbonyl group at C5, not by homoconjugation. The source of the surprising low reactivity of 2 is unknown at this stage. The small diastereoselectivities, exo (1.2) for 1 and endo (2.1) for 2, correlate with relative energies of the diastereomeric pyramidal enolates calculated with AM1. Keywords: enolization, bicyclo[2.2.2]octane-2,5-dione, bicyclo[2.2.2]octane-2,6-dione, AM1, thermodynamic acidities.
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24

Wierschem, Frank, and Karola Rück-Braun. "Introduction of Substituents on the 2-Oxo-piperazine Skeleton by [3+2] Cycloaddition and Subsequent Transformation." Zeitschrift für Naturforschung B 61, no. 4 (April 1, 2006): 431–36. http://dx.doi.org/10.1515/znb-2006-0410.

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The 3,4-substituted 2-oxo-piperazines 5 - 9 are obtained by [3+2] cycloaddition from nitrone 1 and a variety of alkenes. Subsequent functionalization of the bicyclic adducts involves reductive N-O bond cleavage. A route towards libraries of immobilized 1,3-aminoalcohols with a 3,4-substituted 2-oxo-piperazine scaffold is briefly discussed for adducts derived from N-substituted maleic imides
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25

Liu, Qi Mei, Dang Quan Zhang, Kuan Peng, and Wan Xi Peng. "Deep Analysis on Bioindustry Prospects of 40°С Volatiles of Cinnamomum camphora Branches." Key Engineering Materials 480-481 (June 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)- (9.620%), 3-Cyclohexene-1- methanol, .alpha.,.alpha.4-trimethyl- (9.425%), 1,3-Benzodioxole, 5-(2-propenyl)- (8.223%), Bicyclo[2.2.1]heptane, 2-methyl-3-methylene-2-(4-methyl-3-pentenyl)-, (1S-exo)- (7.541%), Tricyclo[2.2.1.0(2,6)]heptane, 1,7-dimethyl-7-(4-methyl-3-pentenyl)-, (-)- (6.884%), Bicyclo[3.1.1] hept-2-ene, 2,6-dimethyl-6-(4-methyl-3-pentenyl)- (6.050%), Bicyclo[2.2.1]heptan-2-one, 1,7,7- trimethyl-, (1S)- (4.678%), 1,3-Benzodioxole, 5-(2-propenyl)- (4.500%), Naphthalene, 1,2,3,5,6,8a- hexahydro-4,7-dimethyl-1-(1-methylethyl)-, (1S-cis)- (4.491%), 3-Cyclohexen-1-ol, 4-methyl-1- (1-methylethyl)-, (R)- (4.254%), Copaene (4.120%), Tricyclo[2.2.1.0(2,6)]heptane, 1,7-dimethyl-7- (4-methyl-3-pentenyl)-, (-)- (4.097%), Acetic acid, 1,7,7-trimethyl-bicyclo[2.2.1]hept-2-yl ester (3.574%), Borneol 3.334%), 3-(4-N,N-Dimethylaminophenyl)propenoic acid, 2- (diethoxyphosphinyl)-, ethyl ester (2.809%), Eucalyptol (2.096%), 1,6,10-Dodecatriene, 7,11- dimethyl-3-methylene-, (Z)- (1.885%), (-)-Isosativene (1.664%), 1,6,10-Dodecatrien-3-ol, 3,7,11-trimethyl- (1.407%), Cyclohexene, 1-methyl-4-(5-methyl-1-methylene-4-hexenyl)-, (S)- (1.218%), 1,4-Methanoazulene, decahydro-4,8,8-trimethyl-9-methylene-, [1S-(1.alpha.,3a.beta., 4.alpha.,8a.beta.)]- (1.174%), .alpha.-Caryophyllene (1.156%), etc. The analytical result suggested that the helium volatiles from the fresh branches of C. camphora can be applicable to biomedicine and spicery industrial materials.
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26

Pal’chikov, V. A., S. A. Prid’ma, and L. I. Kas’yan. "Synthesis and aminolysis of N-(bicyclo[2.2.1]hept-5-en-endo-2-ylmethyl)-N-(oxiran-2-ylmethyl)(7,7-dimethyl-2-oxobicyclo[2.2.1]heptan-1-yl)methanesulfonamide." Russian Journal of Organic Chemistry 50, no. 9 (September 2014): 1312–16. http://dx.doi.org/10.1134/s1070428014090139.

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27

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 derivative18with sodium in liquid ammonia led to amine19, which was used as key intermediate for the construction of (1R*,2R*,3R*,4R*,5R*,6S*)-3-(6-chloro-9H-purin-9-yl)-6-(hydroxymethyl)-bicyclo[2.2.1]heptane-2,5-diol (28) and (1R*,2R*,3R*,4R*,5R*,6S*)-3-(2-amino-6-chloro-9H-purin-9-yl)-6-(hydroxymethyl)bicyclo[2.2.1]heptane-2,5-diol (33). Ammonolysis of28led to 6-amino-9H-purine derivative29. 6-(Dimethylamino)-9H-purine analogue30and 6-(cyclopropylamino)-9H-purine analogues31and34were prepared by aminolysis of corresponding chloropurine derivatives.
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28

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 (June 14, 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’; factor 2 ‘supervision and management of users’; factor 3 ‘parking space’; factor 4 ‘guidance of parking shared bikes’; factor 5 ‘user self-discipline’; factor 6 ‘operation and maintenance’. It requires the cooperation of multiple parties to solve the problem of disorderly parking of shared bicycles.
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29

Moriguchi, Tetsuji, Suvratha Krishnamurthy, Toru Arai, Taisuke Matsumoto, Koji Araki, Akihiko Tsuge, and Norikazu Nishino. "Synthesis and Molecular Structure of tert-Butyl 3-oxo-2-oxa-5-azabicyclo[2.2.2]octane-5-carboxylate." Journal of Crystallography 2014 (August 17, 2014): 1–6. http://dx.doi.org/10.1155/2014/645079.

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The compound tert-butyl 3-oxo-2-oxa-5-azabicyclo[2.2.2]octane-5-carboxylate was synthesized as a cyclic amino acid ester from the corresponding ethyl 2-amino-4-(2-oxiranyl)butanoate HCl salt via an intramolecular lactonization reaction and was characterized by using 1H NMR spectroscopy and high-resolution mass spectrometry. The product was then recrystallized from dichloromethane/diethyl ether and its structure was determined via single crystal X-ray diffraction analysis. The crystal was found to be of the monoclinic space group P21/c (no. 14) with a = 10.217(2) Å, b = 11.676(3) Å, c = 10.273(3) Å, β = 114.186(13)°, and Dcalc = 1.350 g/cm3 at 123 K. The compound has bicyclo[2.2.2]octane structure including a lactone moiety and a piperidine ring, and the two diastereomers of the molecules are present in a 1 : 1 ratio in the crystal.
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30

Buzas, Andrea, and Fabien Gagosz. "Gold(I) Catalyzed Isomerization of 5-en-2-yn-1-yl Acetates: An Efficient Access to Acetoxy Bicyclo[3.1.0]hexenes and 2-Cycloalken-1-ones." Journal of the American Chemical Society 128, no. 39 (October 2006): 12614–15. http://dx.doi.org/10.1021/ja064223m.

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31

KATAYAMA, Sadamu, Hajime HIRAMATSU, Keiichi AOE, and Masashige YAMAUCHI. "Synthesis of 1-Hydroxybicyclo(3.2.1)oct-3-en-2-ones by Acyloin Rearrangement of 1-Methoxy- or 1-tert-Butyldimethylsilyloxy-bicyclo(2.2.2)oct-5-en-2-ones." CHEMICAL & PHARMACEUTICAL BULLETIN 45, no. 9 (1997): 1419–27. http://dx.doi.org/10.1248/cpb.45.1419.

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32

MARUBAYASHI, Nobuhiro, Masami YAMASHITA, and Noriaki HIRAYAMA. "Crystal Structure of .ALPHA.-Bicyclo(2.2.1)hept-5-en-2-yl-.ALPHA.-phenyl-1-piperidinepropanol (Biperiden)." Analytical Sciences 15, no. 8 (1999): 815–16. http://dx.doi.org/10.2116/analsci.15.815.

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33

Goursolle, M., M. Bourhis, and A. H'Naïfi. "Structure du diéthylamino-1 éthyl-6 oxo-7 bicyclo[2.2.1]heptène-5 carboxylate-2 de méthyle." Acta Crystallographica Section C Crystal Structure Communications 42, no. 11 (November 15, 1986): 1641–42. http://dx.doi.org/10.1107/s0108270186091175.

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34

Li, Qing, Dang Quan Zhang, Qi Mei Liu, and Kuan Peng. "Determination of Bioactive Components of 60°С Volatiles from Cinnamomum camphora Branches by TD-GC/MS." Advanced Materials Research 230-232 (May 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[2.2.1]heptane, 2-methyl-3-methylene-2-(4-methyl-3- pentenyl)-, (1S-exo)- (6.143%), 1,6,10-Dodecatrien-3-ol, 3,7,11-trimethyl- (5.365%), Bicyclo[3.1.1] hept-2-ene, 2,6-dimethyl-6-(4-methyl-3-pentenyl)- (4.527%), Naphthalene, 1,2,3,5,6,8a- hexahydro-4,7-dimethyl-1-(1-methylethyl)-, (1S-cis)- (4.129%), 3-Cyclohexen-1-ol, 4-methyl-1- (1-methylethyl)- (2.965%), Borneol (2.627%), Bicyclo[2.2.1]heptan-2-ol, 1,7,7-trimethyl-, acetate, (1S-endo)- (2.586%), Copaene (2.534%), 1,6,10-Dodecatriene, 7,11-dimethyl-3-methylene-, (Z)- (1.612%), (-)-Isosativene (1.121%), etc. The analytical result suggested that the helium volatiles from the fresh branches of Cinnamomum camphora could be used as industrial materials of biomedicines and spicery.
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35

Kräuter, Gertrud, Frank Weller, and Kurt Dehnicke. "Synthesen und Kristallstrukturen der Kronenether-Komplexe [Li3(12-Krone-4)3O2CCH3] [Cd(Se4)2], {[K(18-Krone-6)]2[Hg(Se4)2]}2 und [Na(15-Krone-5)]NO3 / Syntheses and Crystal Structures of the Crown Ether Complexes [Li3(12-Crown-4)33O2CCH3][Cd(Se4)2], {[K(18-Crown-6)]2[Hg(Se4)2]}2, and [Na(15-Crown-5)]NO3." Zeitschrift für Naturforschung B 44, no. 4 (April 1, 1989): 444–54. http://dx.doi.org/10.1515/znb-1989-0412.

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[Li3(12-crown-4)3O2CCH3][Cd(Se4)2] has been prepared by the reaction of [Li(12-crown-4)]2Se6 with Cd(C2CCH3)2 in ethanolic solution. The corresponding polyselenide complex of mercury is formed by the reaction of [K(18-crown-6)]2Se6 with Hg(O2CCH3)2 in the same solvent. Both com pounds form dark red crystals, which were characterized by single crystal X-ray structure determinations. The only product to be isolated from the reaction of Bi(NO3)3·5H2O with [Na( 15-crown-5)]2Se6 in ethanolic solution was [Na(15-crown-5)]NO3, whose structure has also been determined. [Li3(12-crown-4)3O2CCH3][Cd(Se4)2]: space group Pbca, Z = 8. 1404 observed independent reflexions. R = 0.097. Lattice dimensions (19 °C): a = 1981.5(6). b = 1400.3( 1), c = 3268.9(9) pm. The compound forms a dicationic ensemble, in which three lithium ions coordinate with the oxygen atoms of the acetate ion. In the anions the cadmium atom is coordinated tetrahedrally by four selenium atoms of two Se42- units.{[K (18-crown-6)]2[Hg(Se4)2]}2: space group P 1, Z = 1. 3210 observed independent reflexions, r = 0.055. Lattice dimensions (19 °C): a = 1057.4(2). b = 1130.6(2), c = 2000.1(2) pm. α = 88.52(1)°, β = 85.86(1)°, γ = 66.22(1)°. The com pound has a complex ionic structure, in which the formula units form centrosymmetric dimers through K-O contacts between two cations. In addition there are K···Se contacts with the spiro-bicyclic anions, which - together with 6 K-O bonds within the crowns - lead to the coordination number of 8 for the remaining potassium ions.[Na(15-crown-5)]NO3: space group P212121, Z = 4. 1211 observed independent reflexions. R = 0.052. Lattice dimensions (20 °C): a = 912.9(2). b = 989.6(1). c = 1658.3(3) pm. The compound forms ion pairs, in which the sodium atom coordinates with the five oxygen atoms oi the crown ether, as well as with two oxygen atoms of the nitrate ion with Na -O bond lengths of 240 and 247 pm.
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36

Ma, Qing Zhi, Feng Juan Wu¨, Dang Quan Zhang, and Wan Xi Peng. "Analysis on Function Components and Biohealth Function of Phyllostachys heterocycla Biomass." Advanced Materials Research 129-131 (August 2010): 55–59. http://dx.doi.org/10.4028/www.scientific.net/amr.129-131.55.

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Phyllostachys heterocycla, who was considered to have biohealth function in folk, is becoming a major biomass in rooms. Therefore, the chemical components from Phyllostachys heterocycla were identified by TD-GC/MS at different temperature. The main function components of Phyllostachys heterocycla biomass at 40°С were 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester(21.32%), [1,1':3',1''-terphenyl]-2'-ol(9.16%), (2,3-diphenylcyclopropyl)methyl ph enyl sulfoxide, trans-(6.54%), cedrol(6.11%), bicyclo[2.2.1]heptan-2-one, 1,7,7- trimethyl-, (1r)- (6.04%), 1,6-cyclodecadiene, 1-methyl-5-met hylene-8-(1-methylethyl)- (4.82%), 1-heptadecanamine(4.79%), propanedioic acid, methyl-, diethy l ester(4.36%), squalene(4.25%), etc. And the main function components at 60°С were1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester(14.02%), camphor(10.57%), [1,1':3',1''-terphenyl]-2'-ol(6.91%), pentanoic acid, 2-benzenmethanimin yl-5-guanidinyl-(5.68%), 1,6-cyclodecadiene, 1-methyl-5-methyl- (5.27%), cedrol(4.83%), 2-bromo-2,2-dichloroethylcarbamic acid, ethyl ester(4.56%), n-n-butylpropionamide(4.49%), bicyclo[3.1.1]heptane, 6,6-dimethy l-2-methylene-, (1s)- (4.12%), etc. Phyllostachys heterocycla biomass was more healthy to human at 40°С than 60°С. So Phyllostachys heterocycla biomass was fit to use after drying.
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37

Novosjolova, Irina, Dmitrijs Stepanovs, Ērika Bizdēna, Anatoly Mishnev, and Māris Turks. "2,6-Dichloro-9-(2′,3′,5′-tri-O-acetyl-β-D-ribofuranosyl)-9H-purine." Acta Crystallographica Section E Structure Reports Online 70, no. 2 (January 4, 2014): o108—o109. http://dx.doi.org/10.1107/s1600536813034521.

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The title synthetic analog of purine nucleosides, C16H16Cl2N4O7, has its acetylated β-furanose ring in a 3′β-envelope conformation, with the corresponding C atom deviating by 0.602 (5) Å from the rest of the ring. The planar part of the furanose ring forms a dihedral angle of 65.0 (1)° with the mean plane of the purine bicycle. In the crystal, molecules form a three-dimensional network through multiple C—H...O and C—H...N hydrogen bonds and C—H...π interactions.
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38

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 (July 1, 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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39

Peng, Wan Xi, Qiu Xue, Feng Juan Wu, Xu Zhang, and Zhong Feng Zhang. "Analysis on Health Risk of Volatile Organic Compounds of Smoked Bamboo Biomaterial by TD-GC-MS." Key Engineering Materials 467-469 (February 2011): 1697–701. http://dx.doi.org/10.4028/www.scientific.net/kem.467-469.1697.

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Smoked bamboo, which was made by bamboo in high temperature smoke, is a new indoors materials. In order to evaluate its potential health risk to human settlements, the volatile organic compounds of smoked bamboo biomaterial were adsorbed and determined by TD-GC-MS. And the main constituents of volatiles at 60°С were cyclononasiloxane, octadecamethyl-(35.14%), acetic acid(23.27%), cyclotrisiloxane, hexamethyl- (9.53%), bicyclo[4.4.0]dec-1-ene,2-isoprop yl-5-methyl-9-methylene-(7.56%), silane, 1,4-phenylenebis[trimethyl(4.32%), 1,3-benzodioxole, 5-(2-propenyl)- (3.47%), cedrol(2.75%), etc. (2) The main constituents of volatiles at 130°С were acetic acid(43.78%), 2,5-furandione, dihydro-3- methylene-(16.57%), 1,3-benzodioxole, 5-(1-propenyl)-,(z)-(6.75%), octasiloxane, 1,1,3,3,5,5,7,7,9,9, 11,11,13, 13,15,15- hexadecamethyl -(4.09%), bicyclo[2.2.1]heptan-2-one, 1,7,7- trimethyl-, (1s)- (3.21%), etc. Generally, the smoked bamboo biomaterial was safe under 60-130°С.
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40

Kim, JH, MJ Gallagher, and RF Toia. "Methanolysis of 4-Methyl-2,6,7-trioxa-1-phospha-bicyclo[2.2.2]octane 1-Oxide and 1-Sulfide: Mechanistic and Stereochemical Considerations." Australian Journal of Chemistry 47, no. 4 (1994): 715. http://dx.doi.org/10.1071/ch9940715.

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Methanolysis of 4-methyl-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane 1-oxide and 4-methyl-2,6,7- trioxa-1-phosphabicyclo[2.2.2]octane 1-sulfide have been studied by 31P n.m.r. spectroscopy. The trans-2-methoxy-5-methyl-1,3,2-dioxaphosphorinane-r-5-methanol 2-oxide and trans-2-methoxy-5-methyl-1,3,2-dioxaphosphorinane-r-5-methanol 2-sulfide are the initially formed products, respectively, but with time a product mixture comprising the trans- and cis -isomers and the acyclic dimethyl phosphate is formed. Methanolysis of the isolated trans-isomer, and of the isolated acyclic dimethyl phosphate under the same reaction conditions, suggests that the cis -isomer results from a recyclization reaction, rather than from the alternative ring opening of the bicyclic compound.
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41

Shea, K. J., and L. D. Burke. "Bridgehead dienes. Thermal generation of the bicyclo[3.3.1]nona-1(2),4(5)-diene (ZZ) ring system." Tetrahedron Letters 28, no. 7 (January 1987): 735–38. http://dx.doi.org/10.1016/s0040-4039(01)80975-8.

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42

Klunder, A. J. H., F. J. C. Van Gastel, J. M. M. Smits, Paul T. Beurskens, and Gezina Beurskens. "Crystal and molecular structure of (2R,3R)-2-exo-((1R)-1-hydroxy-2-methyl-propyl)-3-exo-hydroxymethyl-bicyclo[2.2.1]-hept-5-ene, C12H20O2." Journal of Chemical Crystallography 25, no. 7 (July 1995): 389–92. http://dx.doi.org/10.1007/bf01665275.

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43

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 (December 1, 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-6-chloro-2,2-dichloro-3-exo/endo-neopentyl-2-silabicyclo[2.2.1]heptanes 5. When the stronger acid CF3SO3H is used no addition to the double bond is observed but only the allyl cleavage takes place to give the triflate 7. The ring opened cyclopentene compounds can be reduced by LiAlH4 to give the corresponding Si-H-compounds 19 and 20. Intramolecular hydrosilylation of 19 leads to the exo/endo-2,2-dimethyl-3-neopentyl-2-silabicyclo[2.2.1]heptanes 21 and so the former bicyclic structure is regenerated.
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44

Scognamiglio, J., C. S. Letizia, and A. M. Api. "Fragrance material review on 1-[5(or 6)-methyl-7(or 8)-1-(methylethyl)bicyclo[2.2.2]oct-5-en-2-yl]ethan-1-one." Food and Chemical Toxicology 62 (December 2013): S61—S66. http://dx.doi.org/10.1016/j.fct.2013.08.066.

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45

Weigelt, Michael, Diana Becher, Eike Poetsch, Clemens Bruhn, Dieter Ströhl, and Dirk Steinborn. "Zur Heck-Reaktion von 1-Chloralk-1-inen - Synthese und Charakterisierung von 1,3-disubstituierten 7-(Prop-2-inyliden)bicyclo[2.2.1]heptanen und anderen Bicyclen." Journal für praktische Chemie 341, no. 5 (July 1999): 477–86. http://dx.doi.org/10.1002/(sici)1521-3897(199907)341:5<477::aid-prac477>3.0.co;2-n.

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46

KATAYAMA, S., H. HIRAMATSU, K. AOE, and M. YAMAUCHI. "ChemInform Abstract: Synthesis of 1-Hydroxybicyclo[3.2.1]oct-3-en-2-ones by Acyloin Rearrangement of 1-Methoxy- or 1-tert-Butyldimethylsilyloxy-bicyclo[2.2.2]oct-5-en-2-ones." ChemInform 29, no. 11 (June 23, 2010): no. http://dx.doi.org/10.1002/chin.199811102.

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47

Kliegel, Wolfgang, Gottfried Lubkowitz, Steven J. Rettig, and James Trotter. "Structural studies of organoboron compounds. LX. Reaction of sterically hindered arylboronic acids with 2-(hydroxyamino)alkanols. Crystal and molecular structure of 2-mesityl-6,6-pentamethylene-1,3-dioxa-4-aza-2-boracyclohexane." Canadian Journal of Chemistry 72, no. 4 (April 1, 1994): 1154–61. http://dx.doi.org/10.1139/v94-147.

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Three 2-(hydroxyamino)alkanols have been reacted with sterically hindered arylboronic acids, ArB(OH)2. When Ar = o-tolyl, 1:2 condensates having bicyclic structures are formed but when Ar = mesityl (2,4,6-(CH3)3C6H2), 1:1 condensates having six-membered cycloboronate structures result. These 1:1 condensates represent the first examples of N-unsubstituted 1,3-dioxa-4-aza-2-boracyclohexane derivatives. An X-ray analysis of one example provides unambiguous proof of the structure. Crystals of 2-mesityl-6,6-pentamethylene-1,3-dioxa-4-aza-2-boracyclohexane, 3c, are monoclinic, a = 11.076(9), b = 23.94(2), c = 13.414(9) Å, β = 109.40(5)°, Z = 8, space group P21/n. The structure was solved by direct methods and refined by full-matrix least-squares procedures to R = 0.051 and Rw = 0.058 for 2037 reflections with I ≥ 3σ(F2).
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48

Piccialli, Vincenzo, Angela Tuzi, and Roberto Centore. "Pseudosymmetry and highZ′ structures: the case ofrac-(2R,2′R,5′S)-2-methyl-5′-[(1R,2R,5S,5′S)-1,4,4,5′-tetramethyldihydro-3′H-3,8-dioxaspiro[bicyclo[3.2.1]octane-2,2′-furan]-5′-yl]-3,4,1′,2′,3′,4′-hexahydro-[2,2′-bifuran]-5(2H)-one." Acta Crystallographica Section E Crystallographic Communications 73, no. 9 (August 1, 2017): 1282–86. http://dx.doi.org/10.1107/s2056989017010805.

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The title compound, C22H34O6, is one of the products obtained by oxidation of squalene with the catalytic system RuO4(cat.)/NaIO4. It crystallizes in theP-1 space group, with four crystallographically independent molecules related by a pseudo-C2symmetry axis. The structural analysis also shows that the title compound is isomeric with two products previously reported in the literature and that are obtained by the same reaction procedure. In particular, out of the seven chiral C atoms present in the molecule, the title compound shows the opposite configuration at, respectively, four and two chiral centres with respect to the isomeric compounds.
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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)-2,2-dimethyl-1,3-dioxan-4,6- dione (4),2,2-dimethyl-5-(7?-oxabicyclo[2.2.1]hept-5?-en-2?-ylidene)- 1,3-dioxan-4,6-dione (5) and 3,4-diazatricyclo[5.2.1.02,6]deca-3,8-diene-endo-cis-2,6-dicarboxylic anhydride (6) gave pyrolysates showing spectra consisting principally of the six strong bands. The observed bands assigned to matrix-isolated butatrienone were at 3105w, 3035s, 3010w, 2964w, 2242s, 1996w, 1495s, 1456s, 728s, 404w cm-1. Calculated frequencies, using various models, for butatrienone are reported and are used to make plausible assignments. The strongest band (v2) attributed to butatrienone was at 2242 cm-1 which was shifted to 2200 cm-1 in (1-13C) butatrienone.
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50

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 to give diethyl 3-(2',2'-diphenylethenylidene)bicyclo[2.2.l]hept-5-ene-2,2-dicarboxylate (10). Alkaline hydrolysis of diester (10) gives an unstable colourless acid and a stable yellow crypto acid shown by X-ray crystallography to be 3-(2',2'-diphenylethenyl)bicyclo[2.2.l]hepta-2,5-diene-2-carboxylic acid (12). Attempts to convert diesters (2) and acid (12) into derivatives suitable for pyrolytic generation of Ph2C=C=C=C=C=O failed; The mono-acid chloride (14) yielded a small phenylazulene fraction on pyrolysis at 780-800°/0.02 mm.
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