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Filtering by: Creator Evans, Evan L. Remove constraint Creator: Evans, Evan L. Advisor White, James D. Remove constraint Advisor: White, James D.

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  • Total synthesis of phorboxazole A

    Creator:
    Lee, Tae Hee
    Abstract:
    The total synthesis of a highly potent cytotoxic marine natural product, phorboxazole A, is described. Both a palladium(II)-mediated and a palladium(II)-catalyzed intramolecular alkoxycarbonylation were used as key steps for the preparation of the two cis-2,6-disubstituted tetrahydropyran rings (C22-C26 and C11-C15) of phorboxazole A. The synthesis used a convergent approach involving...
    Resource Type:
    Dissertation
    Full Text:
    (129). Assembly of two subunits, 130 and 131, employed Evans coupling protocol and provided 141 in

  • Studies towards the total synthesis of (-)-kendomycin

    Creator:
    Smits, Helmars
    Abstract:
    Studies towards the total synthesis of (−)-kendomycin (1), a bacterial metabolite with a unique molecular architecture and pronounced biological activity, are described. These studies resulted in the synthesis of advanced intermediate 208, containing all of the carbon atoms of 1. A Dötz annulation between alkyne 122 and novel chromium carbenoid...
    Resource Type:
    Dissertation
    Full Text:
    , which was used for a syn selective Evans aldol reaction7 with oxazolidinone 9. The desired aldol

  • Studies toward the total synthesis of sanglifehrin A

    Creator:
    Suttisintong, Khomson
    Abstract:
    Studies toward synthesis of subunits of sanglifehrin A, an immunosuppressant featuring a highly substituted [5,5]-spirolactam moiety as well as a 22-membered macrocycle are described. The macrolactone contains a peptidic backbone characterized by an unusual [beta]-substituted (S)-piperazic acid and (S)-m-hydroxyphenylalanine units. These studies resulted in the synthesis of advanced intermediate 358...
    Resource Type:
    Dissertation
    Full Text:
    synthesis of (S)-m- hydroxyphenylalanine derivative 244. Assembly of 244, piperazic acid 113 and L- valine

  • The isolation and structure of leptosphaerin : a metabolite of the marine ascomycete, Leptosphaeria oraemaris (Linder) and A synthesis of the marine toxin, 9-isocyanopupukeanane

    Creator:
    Schiehser, Guy Alan
    Abstract:
    The ethyl acetate extract of the culture filtrate of the marine Ascomycete, Leptosphaeria oraemaris (Linder) yielded a novel metabolite designated by the common name leptosphaerin. An x-ray crystallographic structure analysis was disproved by the synthesis of 3-acetoxy-S-(1,2-dihydroxyethyl)- 3-pyrrolin-2-one 1, starting with N,N-dibenzylhydroxylamine 47 and D-mannitol 44. Oxidation of 47 followed...
    Resource Type:
    Dissertation
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    ethyldiazoacetate to give 4-carboxyethyl-l-methoxy-5-methyltricyclo[5.1.0.03'5]octane 26. Acid catalyzed

  • Studies toward the total synthesis of phorboxazole A

    Creator:
    Kuntiyong, Punlop
    Abstract:
    Studies toward the total synthesis of a highly potent cytotoxic marine natural product, phorboxazole A, were conducted and resulted in a route to an advanced intermediate, C4-C32, for this purpose. A key feature of our approach is the stereoselective synthesis of two cis-2,6-disubstituted tetrahydropyrans present in the macrolide portion of...
    Resource Type:
    Dissertation
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    on studies toward the total synthesis of phorboxazole A. Dr. Christian L. Kranemann, a former

  • Synthetic studies on the macrolide antibiotic rutamycin B

    Creator:
    Wang, Shan
    Resource Type:
    Dissertation
    Full Text:
    NMR spectroscopy. The assignment of absolute configuration to the rutamycins is due to Evans and co­

  • Total synthesis of (+)-bourgeanic acid and conformational analysis of its dilactone

    Creator:
    Johnson, Alan T. (Alan Thomas), 1957-
    Resource Type:
    Dissertation
    Full Text:
    scheme used for hemibourgeanic acid (2). Scheme VIII O OH 0 6.,,..)L ,6,,.,)( H OEt 16 17 tBuMe2SiO

  • Cis-2,5-diaminobicyclo[2.2.2]octane : a novel C₂-symmetric scaffold for asymmetric catalysis

    Creator:
    Shaw, Subrata
    Abstract:
    This thesis describes the development of a new enantioselective synthetic method employing chiral cis-2,5-diaminobicyclo[2.2.2]octane-based organometallic catalysts. The significance of this new method to organic synthesis is illustrated with preparation of enantioenriched products that are transformed to important pharmaceutical agents. Chapter 1 provides a brief historical overview of asymmetric catalysis, especially...
    Resource Type:
    Dissertation
    Full Text:
    as single enantiomers. For example, mammalian proteins are composed exclusively of L-amino acids and

  • Synthesis of epothilones and epothilone analogues

    Creator:
    Sundermann, Kurt F.
    Abstract:
    A convergent synthesis of epothilone B that generates all seven of its asymmetric centers in a completely stereoselective fashion has been completed. Key reactions include an anti-Felkin aldol condensation to set the C6 and C7 stereochemistry, a directed α-hydroxylation to install the C15 (S)-hydroxyl substituent, and a Wittig condensation to...
    Resource Type:
    Dissertation
    Full Text:
    Epothilone B10 (11) NtS.OH Epothilone G1 (12), R = H Epothilorie G2 (13), R Me L/,SS0H Epothitone H1 (14

  • Approaches to the synthesis of trichothecane sesquiterpenes

    Creator:
    Thomas, James Anthony
    Resource Type:
    Dissertation
    Full Text:
    . Mario Boschetto for his wizardry with glassware. Finally, I wish to acknowledge the N. L. Tartar