Dissertations / Theses: 'Cyclohexenones'

1

Clark, R. S. J. "The synthesis of cyclohexenones by rearrangement of bicyclo(2,2,2)octanones." Thesis, University of Cambridge, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356675.

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2

Sheth, Ritesh B. "Development of new synthetic methodologies and the synthesis of natural products." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 101 p, 2010. http://proquest.umi.com/pqdweb?did=1993336351&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.

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3

Williams, Katharine. "Investigation of a synthetic approach to polyfunctionalised cyclohexenones related to the antheminone and carvotacetone natural products." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/investigation-of-a-synthetic-approach-to-polyfunctionalised-cyclohexenones-related-to-the-antheminone-and-carvotacetone-natural-products(bab498dd-4ab6-4f07-81f1-72b29cbb2f60).html.

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The natural product 2 crotonyloxymethyl-(4R,5R,6R)-4,5,6-trihydroxy-cyclohex-2-enone (COTC) was isolated from the microorganism Streptomyces griseosporeus in 1975. It was shown to exhibit 'cytotoxic and cancerostatic activity'. The simplified synthetic analogue 2-crotonyl-oxymethyl-cyclohex-2-enone (COMC) has been shown to exhibit potent anti tumour activity against murine and human tumours in cell culture. For several years, the Whitehead research group at the University of Manchester have focused on the synthesis of COTC and COMC analogues in an attempt to produce compounds with enhanced cytotoxicity. In this thesis, the syntheses of several polyfunctionalised cyclohexenones are described. These compounds are analogues of COTC and COMC which also bear structural resemblance to the antheminone and carvotacetone natural products. Initially, the syntheses of six novel compounds from the chiral pool starting material (-)-quinic acid are described. The first four synthetic steps of each sequence were carried out by slight modification of procedures previously reported by the Whitehead research group. As part of the synthetic strategy, the diastereoselective conjugate addition of carbon nucleophiles to several polyfunctionalised cyclohexenones was investigated. The cytotoxicity of four of the synthetic analogues towards A549 non small cell lung cancer cells was investigated by use of an MTT assay. Two of the analogues were found to be more cytotoxic then COMC. The most effective synthetic analogue had an IC50 value of 2.2 μM. This analogue was more cytotoxic than similar molecules that had previously been synthesised by members of the Whitehead research group. Based on the results of the MTT assay, another two analogues were designed and their synthesis from (-)-quinic acid is described. The cytotoxicity of these analogues has yet to be assessed. In summary, the general synthetic strategies developed in this thesis will provide easy access to new analogues of the natural products, enabling the development of new cytotoxic compounds.

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4

Paramahamsan, Harinandini. "η⁶-Arenechromium Tricarbonyl Complexes: Conformational Analysis, Stereocontrol in Nucleophilic Addition and Applications in Organic Synthesis." Case Western Reserve University School of Graduate Studies / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=case1106262785.

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5

Kasprzyk, Milena, and milena kasprzyk@freehills com. "Synthetic Studies Towards the Tridachione Family of Marine Natural Products." Flinders University. Chemistry, Physics and Earth Sciences, 2008. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20081107.085933.

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Since the middle of the 20th century, significant interest has evolved from the scientific community towards the polypropionate family of marine natural products. A number of these compounds have been shown to possess significant biological activity, and this property, as well as their structural complexity, has driven numerous efforts towards their synthesis. The first chapter provides an introduction into the world of polypropionates, with a discussion on synthetic studies into a number of members of the tridachiapyrone family. Fundamental synthetic concepts utilised in this thesis towards the preparation of polyketides are also described, with a focus on their application towards the synthesis of 9,10-deoxytridachione, anti tridachiahydropyrone and syn tridachiahydropyrone. Chapter 2 describes the work undertaken towards the total synthesis of 9,10-deoxytridachione. The novel tandem conjugate addition-Dieckmann condensation of complex enones developed previously in the Perkins group was used to generate anti methylated cyclohexenones as key synthetic intermediates. The conversion of the cyclohexenones into the corresponding cyclohexadienes via allylic alcohols was attempted, utilising a Grignard-mediated reaction to achieve the selective 1,2-reduction. Studies into the Grignard-mediated reduction were also undertaken on seven additional cyclohexenones, in order to investigate the utility and scope of the reaction. The extension of the methodology previously developed for the synthesis of cyclohexenones is the subject of Chapter 3. This section describes investigations into the synthesis of stereochemically-diverse cyclohexenones from complex enones. The conjugate addition-Dieckmann condensation strategy was extended successfully towards the synthesis of a syn methylated cyclohexenone, which allowed the synthesis of the proposed true structure of tridachiahydropyrone to be pursued. The methodology developed in Chapter 3 was utilised in Chapter 4 to synthesise a model system of syn tridachiahydropyrone. A comparative analysis of the NMR data of the syn model, an anti model and anti tridachiahydropyrone with the natural product indicated that the true structure of tridachiahydropyrone may indeed have syn stereochemistry. The synthesis of syn tridachiahydropyrone was attempted, and to this end a suitable cyclohexanone was successfully synthesised. However, the subsequent methylation-elimination cascade failed to furnish the desired syn methylated cyclohexenone, producing only an anti methylated cyclohexanone. The stereochemistry of the methylation was deduced using high and low variable temperature NMR coupled with selective irradiation NOESY.

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6

Ohnemüller, Ulrike. "Effiziente Synthese hochsubstituierter enantiomerenreiner Cyclohexenone und Tetrahydroxanthenone." Berlin Logos-Verl, 2005. http://deposit.ddb.de/cgi-bin/dokserv?id=2793052&prov=M&dok_var=1&dok_ext=htm.

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7

Ohnemüller, Ulrike Kerstin. "Effiziente Synthese hochsubstituierter enantiomerenreiner Cyclohexenone und Tetrahydroxanthenone /." Berlin : Logos Verl, 2006. http://deposit.ddb.de/cgi-bin/dokserv?id=2793052&prov=M&dok_var=1&dok_ext=htm.

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8

Jaunet, Alex. "Synthetic approaches to naturally occuring cyclohexenone epoxides." Thesis, University of Sheffield, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505527.

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9

Chen, Jianxin. "A study of the photorearrangements of crystalline dibenzobarrelene and cyclohexenone derivatives." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30985.

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Two series of compounds, 4,4-diarylcyclohexenones and 9-substituted dibenzobarrelenes, were synthesized and their photochemistry was investigated in the crystalline state and in solution medium. The differences in photoreactivity and product selectivity of these compounds between the solution and solid states have been determined, and possible structure-reactivity correlations are discussed based on X-ray crystallographic data for some of the substances. The photorearrangement of 4,4-diarylcyclohexenones was found to be affected moderately by the crystal lattice. The migratory aptitude of the aryl groups for 4-phenyl-4-arylcyclohexenones was shown to be controlled to a lesser extent by the electronic effect in the solid state compared to solution. Irradiation of 4,4-diphenyl-6-methyl-cyclohexenone in the crystalline phase gave the same photoproducts and a similar product distribution as that in the solution phase. In this case, conformational analysis reveals that both pseudo-axial and pseudo-equatorial phenyl groups of the enone moiety are capable of migrating. The di-π-methane rearrangement of a number of 9-substituted dibenzobarrelene derivatives gave two regioisomeric dibenzo-semibullvalene products upon photolysis in solution and in the solid state. In general, the effect of the crystalline environment on the reaction regioselectivity is found to be small. Resolved chiral substituents (handles) at the 9-position of the dibenzobarrelene moiety were used to force the compounds to crystallize in chiral space groups. Asymmetric inductions via photolysis of the chiral crystals varied from small to moderate depending on the nature of the chiral substituent. It was found that, in some cases, asymmetric induction in the solid state is significantly higher than in solution, but is lower in one instance. In addition, the chiral crystalline environment has different effects on the asymmetric inductions in a dual pathway di-π-methane rearrangement. The di-π-methane photorearrangement of 9,12-bridged dibenzobarrelene lactones was found to proceed very efficiently in solution and in the solid state. The unusual regioselectivity observed was rationalized in terms of an intramolecular steric effect rather than an electronic stabilizing effect. An absolute asymmetric synthesis with high optical yield was achieved by photolyses of chiral crystals of the achiral compound, methyl 3,5-dihydro-3-oxo-1H-5,9b[1',2']benzeno-naphtho[1′,2′-c]furan-4-carboxylate. Photochemical [2+2] cycloaddition of this substrate to 1,3-dienes was found to be mechanistically interesting, involving an excited triplet state of 1,3-diene which is formed by energy transfer. An unusual excited singlet state rearrangement of 9-chloromethyl substituted dibenzobarrelene diester was discovered. X-ray crystallographic analyses revealed that an intermolecular chlorine atom transfer is involved in the formation of unusual dibenzopentalene photoproducts. Finally, a novel solid state photochromism was found, and a radical species was proposed as the intermediate responsible for the observed photochromic phenomenon.
Science, Faculty of
Chemistry, Department of
Graduate

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10

Moralee, Andrew Charles. "The synthesis of geminally difluorinated cyclohexenols via Diels-Alder chemistry." Thesis, University of Birmingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391382.

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11

Hwang, Christine. "Crystal structures and solid state reactions of maleic anhydride and of a cyclohexenone and its photoproduct." Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/27966.

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Two sets of structures were determined by X-ray crystallographic techniques, one of maleic anhydride (2,5-furandione) and the other of 4-phenyl-4-p-bromophenylcyclohex-2-en-1-one and its photoproduct, trans-5-phenyl-6-p-bromophenylbicyclo[3.1.0]hexan-2-one. Analysis of maleic anhydride included a room temperature redetermination of the crystal structure. This was done to improve parameters and simplify comparison of the room temperature and low temperature data. The structure determination at 104k resulted in the location of bonding electrons in the double bond. Thermal motions of both sets of data showed that translational motion was greatest along an axis parallel to the carbonyl bonds. Libration was found to be greatest about this axis also. The second set of structures was done to examine the migration pattern of aryl groups upon irradiation of a diarylcyclohexenone. The major photoproduct was formed by migration of the p-bromophenyl group. The resulting bicyclohexanone had the aryl groups trans to each other.
Science, Faculty of
Chemistry, Department of
Graduate

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12

Boulet, Serge L. "Total syntheses of (±)-neoverrucosan-5(ß)-ol, (±)-homoverrucosan-5(ß)-ol, (±)-verrucosan-2(ß)-ol, and (±)-(3R,4R, 5R, 6S, 9R)-cyatha-12, 18-diene, a new cyclohexenone annulation sequence." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ34515.pdf.

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13

Xing, Dongxia. "Stereoselective Solid-State NaBH₄ Reduction of 1-Methylpentacyclo[5.4.0.0²,⁶.0³,¹⁰,0⁵,⁹]undecane-8, 11-Dione, Synthesis and Chemistry of Strained Alkenes, and Chemical and Microbial Synthesis of Racemic and Optically Active (S)-4-Hydroxy-2-Cyclohexenone." Thesis, University of North Texas, 1995. https://digital.library.unt.edu/ark:/67531/metadc278368/.

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Part I. Reduction of the 1-methylpentacyclo [5.4.0.0²,⁶.0³,¹⁰,0⁵,⁹]undecane-8, 11-dione (9) with solid NaBH₄ resulted in highly stereoselective reduction of both C=O groups in the substrate, thereby affording the corresponding endo-8, endo-11-diol (11a). The configuration of 11a was established unequivocally by converting 11a into the corresponding cyclic thiocarbonate ester, 12. Part II. Z-1,2-Di(1'-adamantyl)ethene (14) was synthesized with a high degree of stereoselectively in four steps (Scheme 9 in Chapter 2). E-1,2-di(1'-adamantyl)ethene (15) was synthesized by iodine promoted isomerization of 14. Both structures were established unequivocally via single-crystal X-ray structural analysis. E-1-(exo-8'-Pentacyclo[5.4.0.0²,⁶.0³,¹⁰,0⁵,⁹]undecyl)-2-phenylethylene (16a) was synthesized, and its structure was established via analysis of its 1H, 13C, and 2D COSY NMR spectra. Part III. Reactions of electrophiles, i.e.,:CCl_2, PhSCl, and Br_2, to Z- and E-1,2-di(1'-adamantyl)ethenes (14 and 15, respectively) are described (Scheme 5, 8, 10, and 13 in Chapter 3). Structures of the corresponding products were established unequivocally via analysis of their respective one- and two-dimensional NMR spectra and/or single-crystal X-ray structural analysis. Part IV. An improved asymmetric synthesis of optically active (S)-4-hydroxy-2-cyclohexenone 1 (64%ee, determined via Mosher's method) has been developed (Scheme 5 in Chapter 4). The key step in this synthesis involves the baker's yeast reduction of 13. The absolute configuration of the major product, (S)-1, was established unequivocally via single-crystal X-ray structural analysis of a precursor. The optical purity of the major product 14a (80%de, 67%ee) was established via careful integration of relevant gated-decoupled 13C NMR spectra.

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14

Chien, Chiung-Fang, and 簡瓊芳. "The Diels-Alder Reaction of Alpha-Diethoxyphosphinyl-cyclohexenones and Applications." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/22883444593753937438.

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碩士
國立清華大學
化學系
89
Abstract The Diels-Alder cycloaddition reaction of -diethylphosphonyl cyclohex-2-en-1-ones 34 and 37 and subsequent transformations of resulting cycloadducts are described in this thesis. Part one dscribes the Diels-Alder cycloaddition reaction of enones 34 and 37, which were synthesized using known procedures. Enones 34 and 37 were found to be effective dienophiles, giving the expected cycloadducts in good to excellent yields and within a reasonable period of time. The reaction was found to follow the ortho- and para- rules and gave the endo-to-ketone product. Of all the Lewis acids investigated, tin chloride was deemed to be the most effective Lewis acid. Part two describes the use of lithium naphthalenide as an efficacious reducing agent in the removal of the angular alkyl phosphonyl group in the above-formed cycloadducts. The resulting enolate was then trapped with a variety of alkylating agents, giving in all cases, a cis-ring junction. Part three describes an interesting use of the phosphonate containing cycloadducts mentioned above in a Wittig type reaction. The above- formed cycloadducts were first treated with a variety of Grignard reagents. The resulting 1,2-adducts 68 and 69 were then treated with potassium hydride in the presence of 18-crown-6 to give various rearrangement products 70 and 71.

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15

Wang, Bingbing. "Photochemistry of 6-alkenyl-2-cyclohexenones : synthetic studies towards precursors of ryanodol." Thesis, 1998. http://hdl.handle.net/1957/33725.

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Regiochemistry of intramolecular [2+2] photocycloadditions of oxygenated 6-alkenyl-3-alkoxy-2-cyclohexenones is studied. Application of this methodology to construct a key intermediate [3.3.2] bicyclic skeleton of ryanodol is described as well. Irradiation of (3-butenyl)compounds 3, 11, 14 and of (4-pentenyl)compound 6 afforded exclusively the linear photoadducts 4, 12, 15 and 7 respectively. Irradiation of allyl compound 25 brought the desired crossed photoadduct 26. The structures of the photoadducts 4, 7 and 26 were assigned based on spectroscopic analysis and confirmed by subsequent retroaldol cleavage reactions of the corresponding photoproducts. The regiochemistry of linear adduct 15 was deduced by a sequence of transformations. Retroaldol cleavage of the photoadduct 15, followed by transannular reductive coupling with SmI��, and hydrolysis of the protecting group provided triol 18. PDC oxidation of 18 gave [4.2.2] bicyclic triketone 20 and a cyclic hemiketal 21. Finally, Swern oxidation of 18 confirmed both isomers of photoproduct 15 are linear adducts. Selective retroaldol ring opening of compound 26 resulted in the formation of the bicyclo[3.3.1]nonane skeleton, amenable through a one carbon ring expansion to establish the core bicyclo[3.3.2]decane system in ryanodol.
Graduation date: 1998

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16

Baker, Mark Robert. "The synthesis and photorearrangements of allenic analogues of cyclohexenones and 2,5-cyclohexadienones an investigation of allenic excited states /." 1992. http://catalog.hathitrust.org/api/volumes/oclc/27750476.html.

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17

Chen, Liang-Hsun, and 陳亮勳. "Part I. An Indium Promoted Asymmetric Allylation in Aqueous Cyclodextrin Solution Part II. Photochemistry of Cyclohexenones Containing Cyclopropyl Coumpounds." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/18366037569543051615.

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碩士
國立交通大學
應用化學系
92
Part I. An Indium Promoted Asymmetric Allylation in Aqueous Cyclodextrin Solution In this thesis we discussed about the allylation reaction promoted by indium using cyclodextrins as an auxiliary in aqueous solution. The effects of indium equivalent, cyclodextrin concentrations and solution temperature were studied, and the allyl aryl alcohols were obtained in 60~90% yield and a maximum of 24% e.e. was achieved. The failure to achieve a high e.e. value when using cyclodextrins as an auxiliary is due to the shallow binding of cyclodextrin complexes and a dynamic equilibrium exists in the guest and host (CD), therefore only a small difference in the stereo-selectivity was achieved. Part II. Photochemistry of Cyclohexenones Containing Cyclopropyl Coumpounds In the second part of this work, we have studied the photochemistry of cyclohexenone compounds containing cyclopropyl group, i.e. 74 and 75. The expected ring-opening reactions of these cyclopropyl containing compounds were not observed, instead, compound 74 underwent a photo-[2+2]cycloaddition to yield 76. The configuration of compound 76 was assigned to be an anti-hh dimmer based on its 1H- and 13C NMR spectra and its similarity in chemical shifts with known structures. The anti-hh 76 was latter confirmed by an X-ray crystallographic analysis. Compound 75 underwent a Photo-Fries rearrangement and also gave compound 77 as the sole product. The structure of compound 77 was also confirmed by NMR and X-ray studies. Presently the reaction mechanism is not known.

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18

Zuraw, Michael John. "The investigation of organic photochemical reactions in crystalline solids the solid state photochemistry of cyclohexenones and di-[pi]-methane systems /." 1989. http://catalog.hathitrust.org/api/volumes/oclc/22377036.html.

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19

Wen-Yueh, Ho, and 何文岳. "Study of Intramolecular Radical Cyclization Reac- tions of Cyclohexenone." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/46233644151257648711.

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20

Wang, Hui-Ling, and 汪惠玲. "Photochemistry of Cyclohexenone Derivatives and the Syntheses of cis-Theaspirone, (ent)-Grindelic Acid and Dicyclopenta[a, d]cyclooctenes." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/52206275469465934403.

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21

St, Clair Jerry Dale. "Electronic and steric control of photochemical migratory aptitudes the photochemistry of 4-(1-naphthyl)-4-(2-naphthyl)-2-cyclohexenone /." 1988. http://catalog.hathitrust.org/api/volumes/oclc/19586851.html.

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22

Boulet, Serge L. "Total synthesis of (+-) neoverrucosan-5B-ol, (+-)-homoverrucosan-5B-ol, (+-)-verrucosan-2B-ol, and (+-)-(3R,4R,5R,6S,9R)-cyatha-12,18-diene : a new cyclohexenone annulation sequence." Thesis, 1998. http://hdl.handle.net/2429/9454.

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The total syntheses of four structurally related, naturally occurring compounds, (±)verrucosan-2β-ol (61), (±)-neoverrucosan-5β-ol (62), (±)-homoverrucosan-5β,-ol (63), and (±)-(3R, 4R, 5R, 6S, 9#)-cyatha-12,18-diene (64) are discussed in the first part of this thesis. In connection with the total syntheses of the natural products 61-64, a new bifunctional reagent mediated cyclohexenone annulation sequence was developed, but attempted application of this sequence to the natural product syntheses was not successful. The generality, scope and synthetic utility of this new annulation method are described in the second part of this thesis. The syntheses of the natural products 61-64 started with the conversion of 3 methylcyclohex-2-en-l-one (140) into the known bicyclic enone 179. Recently developed methodology from our laboratory was used as a key step and involved the stereoselective conjugate addition reaction of the cuprate reagent 192 to the enone 179 with control of the 5,6 ring-juncture stereochemistry to afford the ketone 60. A double alkylation of 60, first with the bifunctional reagent 281, and then with methyl iodide, provided the ketone 287. Functional group manipulations were used to convert 287 into 273, which underwent an aldol cyclization-dehydration sequence to provide the corresponding enone 72. Dissolving metal reduction of the latter material afforded the tricyclic ketone 171. From compound 171, diverging synthetic routes gave the cyathane natural product 64 and the three verrucosanetype natural products 61-63. Ring expansion of 171 and functional group manipulations led to 64. Conversion of 171 into the tricyclic enone 174 involved a series of functional group transformations. Separate synthetic routes from compound 174 led to (±)-neoverrucosan-5βol (62) or (±)-verrucosan-2β-ol (61), both of which reacted with acid to produce (±) homoverrucosan-5 (5β-ol (63). The four racemic natural products were tested against the P388 murine leukemia cell line and possessed cytotoxicity with ED₅₀'s in the range of 1.7 21 µg/mL. The newly developed cyclohexenone annulation sequence involved alkylation of N,Ndimethylhydrazones of general structure 32 with the Afunctional reagent 253 to provide 354. Conversion of 354 into the keto alkenyl iodide 356, followed by n-BuLi-mediated cyclization of 356 and oxidative rearrangement of the resultant allylic alcohol 358 provided the cyclohexenone 359. Each step is experimentally simple, tolerates a variety of ring sizes and functionality, and proceeds in very good yield. [Formula]

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23

Lin, Huang Jian, and 黃建霖. "Design, Synthesis,and Evaluation as Inhibitors of 4-Hydroxyphenylpyruvate Dioxygenase and Synthesis and Evaluation of 3-Hydroxy-2-(2-nitrobenzoyl)2-cyclohexenone as a Selective Protecting Group for Primary Amines." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/59076390669826684076.

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Dissertations / Theses on the topic 'Cyclohexenones'

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