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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
641

Microwave synthesis and molecular re-arrangement of a grisadienone and its derivatives

Ngcobo, Thandekile Sithembile January 2011 (has links)
Submitted in fulfilment of the requirements for the Degree of Master of Technology: Organic Chemistry, Durban University of Technology, 2011. / ortho-Deoxygrisan (38), a spirodienone was synthesised from bisphenol (42) using both conventional and microwave assisted methods. The bisphenol (42) was synthesised from phenol (52) by conventional and microwave assisted methods. Benzophenone (43) was synthesised from compound (49) which in turn was synthesised from compound (53) by chromic acid oxidation in acetic anhydride or acetic acid. Compound (53) was synthesised from bisphenol (42) by mono-acetylation method.Acid-catalysed rearrangement of ortho-deoxygrisan (38) in the absence of light was investigated. Chromatography of the reaction mixture afforded compound (D) as a major component. Attempts to synthesise ortho-grisan (50) from benzophenone (43) were unsuccessful. Microwave assisted selenium dioxide oxidation of compound (53) gave a yellow compound C. The spectra of this compound were very similar to the spectra of ortho-deoxygrisan (38). However, selenium dioxide was reacted with compound (53) in the absence of microwave to give a yellow solid B. The 1H NMR spectral data of this compound led to the proposed structure B for it. / National Research Foundation.
642

I. DIELS-ALDER REACTIONS OF TRIMETHYL CYCLOPENTADIENYL STANNANE. II. PREPARATION AND DIELS-ALDER REACTIONS OF VINYLSULFOXIMINES.

REINEKE, KARL EDWARD, II. January 1983 (has links)
In Part 1, the Diels-Alder adducts of trimethyl cyclopentadienylstannane (I.3) with maleic anhydride and fumaronitrile are prepared in 61% yield. The molecular structure of the adduct with maleic anhydride (1.6) is unequivocally established as 7-syn-trimethy1stannyl-endo- bicyclo[2.2.1]hept-5-enyl-2,3-dicarboxy1ic anhydride by single crystal X-ray structure analysis. In Part II, the high yield preparation of some new S-a1ky1-Saryl- N-p-toluenesu1fonylsu1foximines, by ruthenium tetroxide oxidation of the corresponding su1filimine, is described. Dehydrochlorination of S-chloroethy1-N-p-toluenesu1fonyl-S-p-toly1su1foximine and its S-phenyl analog with triethylamine gives the previously unknown N-p-to1uenesu1fony1- S-p-to1y1-S-viny1sulfoximine (II.17) and its S-phenyl analog. The Diels-Alder reaction of II.17 with a variety of 1,3-dienes and the known N-phtha1imido-S-p-tolyl-vinylsu1foximine (11.14) and the previously unreported S-p-nitropheny1-N-phtha1imido-viny1su1foximine (11.39) with cyclopentadiene are described. All of the reactions give mixtures of the possible adducts. The configuration of the major diastereomer (II.19d) of the adducts of II.14 with cyclopentadiene is known from a single crystal X-ray structure analysis. The structures of the other adducts are determined by ¹H NMR spectroscopic analysis. Chemical correlation of II.19d with the adducts of II.17 with cyclopentadiene confirm the assignment made by ¹H NMR. A competition Die1s-Alder reaction between II.17 and p-toly1-viny1sulfone shows that the vinylsulfoximine is more reactive. Sodium amalgam reduction of the cyclohexadienyl adducts of II.17 gives bicyclo[2.2.2Joctene and hydrazine in allyl alcohol reduction of adduct II.19d gives the corresponding sulfoxide II.20d.
643

Robotic chemical synthesis using forth as an interactive development environment

Zsótér, András. January 1996 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
644

Studies toward the total synthesis of biologically active cyclodepsipeptides

彭向榮, Pang, Heung-wing. January 2002 (has links)
published_or_final_version / Chemistry / Master / Master of Philosophy
645

Resonance Raman, time-resolved resonance Raman and density functional theory study of Benzoin diethyl phosphate, selected P-Hydroxy and P-methoxy substituted phenacyl ester phototrigger and model compounds

Chan, Wing-sum., 陳穎心. January 2005 (has links)
published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy
646

Density functional theory studies of selected transition metals catalyzed C-C and C-N bond formation reactions

Lin, Xufeng., 林旭鋒. January 2007 (has links)
published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy
647

Catalytic C-H bond functionalization reactions catalyzed by rhodium(III) porphyrin, palladium(II) and platinum(II) acetatecomplexes

Thu, Hung-yat., 杜鴻溢. January 2006 (has links)
published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy
648

Time-resolved spectroscopic studies of the photophysics and photochemistry of selected benzoin and benzophenone compounds

Du, Yong, 杜勇 January 2008 (has links)
published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy
649

Design, synthesis, luminescene and photochromic studies of dithienylethene-containing nitrogen and mixed nitrogen-oxygen donorligands and their complexes

Lee, Ho-man., 李浩文. January 2009 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
650

Environmental impacts and management of persistent organic pollutants in South China

Lau, Hoi-yin, Melody., 劉凱賢. January 2009 (has links)
published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

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