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Filtering by: Creator Helfand, Stuart C. Remove constraint Creator: Helfand, Stuart C. Academic Affiliation Chemistry Remove constraint Academic Affiliation: Chemistry Degree Name Doctor of Philosophy (Ph.D.) Remove constraint Degree Name: Doctor of Philosophy (Ph.D.)

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  • Studies on the metabolism on n-propyl N, N-di-n-propyl thiolcarbamate in legumes

    Creator:
    Bourke, John Butts
    Abstract:
    The absorption, translocation and metabolism of a new herbicide, n-propyl-C¹⁴ N, N-di-n-propyl-thiolcarbamate (PDPC), were studied in both peanut and soybean plants. These studies were carried out on plants of different ages and treated at two rates of application. The residue content of the plants was also determined from germination to...
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    Dissertation
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    it into ethanol soluble components" The abillty to convert the herbicide into respiratory c;rrbon

  • Biosynthesis of blasticidin S : mechanistic and stereochemical investigations

    Creator:
    Prabhakaran, P. C.
    Abstract:
    Feeding of [3-¹³C, 2-¹⁵N]arginine, 38a, unequivocally established that the β- arginine moiety of blasticidin S, 1, was formed from α-arginine by an intramolecular migration of the α-amino group to the β- position. Further feedings using chirally deuteriated arginines 38e and 38f revealed that the aminomutase process occurred with inversion of...
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    Dissertation
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    stereochemical investigations AN ABSTRACT OF THE THESIS OF P. C. Prabhakaran for the degree of Doctor of

  • Enantioselective Total Syntheses of Quinolizidine Lycopodium Alkaloid Cermizine D and Cytotoxic Marine Macrolide Mandelalide A

    Creator:
    Veerasamy, Nagarathanam
    Abstract:
    The enantioselective total synthesis of quinolizidine-containing natural product cermizine D and formal syntheses of senepodine G and cermizine C has been achieved. These natural products are members of the lycopodium alkaloids, which have attracted significant attention due to their exciting biological activities and the diverse structural scaffolds. Key steps in...
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    Dissertation
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    product cermizine D and formal syntheses of senepodine G and cermizine C has been achieved. These

  • Low temperature thermal analysis of some boron halide complexes with weak Lewis bases

    Creator:
    Lerch, Ronald Edwin
    Abstract:
    Thermal analysis was used to investigate the following seven systems: H₂S-B₂F₄, SOF₂-B₂F₄, COC1₂-B₂F₄, SF₄-B₂F₄, Xe-BF₃, NF₃-BF₃, and NF₃-BC1₃. In two of the seven systems compound formation was observed. In the system, H₂S-B₂F₄ the compounds H₂S[superscript .]B₂F₄ and 2H₂S[superscript .]B₂F₄ are formed. The compound H₂S[superscript .]B₂F₄ has a melting point of...
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    Dissertation
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    B2F4 has a melting point of -94, 9 ± 0, 3° C while the compound 2H2S B2F4 melts at - 100. 3 O. 3° C

  • Steroid organoborane reactions

    Creator:
    Byall, Elliott Bruce
    Abstract:
    Steroid organoboranes have been found to be useful synthetic intermediates. Attempted pyrolyses, based on simple trialkylborane cyclizations, have not yielded C-19 or C-18 functionalized steroids, but have produced isomerized systems not otherwise available. Thus, hydroboration of cholesterol followed by pyrolysis at 215° gives 31% of 2-cholestene-6α-ol and 49% of a...
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    Dissertation
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    pyrolyses, based on simple trialkylborane cyclizations, have not yielded C -19 or C -18 functionalized

  • Total Synthesis of Tryptamine Alkaloids from the Arundo and Leuconotis Genera

    Creator:
    Ferreira, Andrew
    Abstract:
    The first part of this manuscript is about the total synthesis of the Arundo donax bis(indole) natural products. The A. donax alkaloids were prepared using the first example of an ynindole Diels–Alder reaction. Each were then separated, isolated, and determined to have stable enantiomeric conformations at room temperature (Chen, J.;...
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    Dissertation
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    enantiomeric conformations at room temperature (Chen, J.; Ferreira, A. J.; Beaudry, C. M. Angew. Chem. Int

  • Studies on the biosynthesis of the streptolidine moiety of streptothricin F

    Creator:
    Wityak, John
    Abstract:
    The loss of all deuterium labels from previous feedings of [2-²H]-, [3,3-²H₂]-, and [2,3,3-²H₃]arginines had indicated the possible intermediacy of β-hydroxy- and β-ketoarginine (30 and 31, respectively) in the biosynthesis of the streptolidine portion of streptothricin F (la). In order to confirm or refute this evidence, D,L-[2,3,3,5,5-²H₅]- arginine (32) was...
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    Dissertation
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    material generated 1 a labeled at C-4 and at C-3 of the streptolidine portion, fully in agreement with such

  • Intercalation, exfoliation, and nanocomposites of layered inorganic compounds

    Creator:
    Sukpirom, Nipaka
    Abstract:
    The melt intercalation of poly(ethylene oxide) (PEO) between layers of MoO₃ and MPS3 (M=Mn,Cd) is obtained by heating the ground mixture and LiₓMoO₃, KₓMn₁-ₓ/₂PS₃, or KCd₁-ₓ/₂PS₃. The products are characterized by powder X-ray diffraction (XRD). Below the melting temperature of PEO (66 °C), intercalation rates and yields are low. By...
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    Dissertation
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    diffraction (XRD). Below the melting temperature of PEO (66 °C), intercalation rates and yields are low. By

  • Computational Investigation into the Mechanisms and Origins of Selectivity in Selected Organic and Organometallic Chemical Processes

    Creator:
    Harper, Jordan L.
    Abstract:
    Put generally, the work I have conducted in my time at Oregon State University has been to answer two questions. The first of these is “Why do I get this particular product from this particular chemical reaction?” and the second is “How do the reagents in this chemical reaction lead...
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    of an organo-catalytic Claisen rearrangement led to the observation that an interaction between a C

  • Excited state molecular structural evolution and chemical reactivity studied by femtosecond stimulated Raman spectroscopy

    Creator:
    Han, Fangyuan
    Abstract:
    In this dissertation, my research work on excited state dynamics of small organic molecules in solutions is presented. Using femtosecond stimulated Raman spectroscopy (FSRS) as the main experimental tool, the excited state hydrogen-bonding dynamics (ESHBD) of Coumarin 102, a common laser dye molecule, in ethanol solution is examined with <150...
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    Dissertation
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    spectator mode, i.e. the C=O stretching mode, is examined within a 600 ps time window. The excited state