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Filtering by: Creator Nielsen, James F. Remove constraint Creator: Nielsen, James F. 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:
    : James D. White The total synthesis of a highly potent cytotoxic marine natural product

  • 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:
    :_____________________________________________________ James D. White Studies towards the total synthesis of (−)-kendomycin (1), a bacterial

  • Studies toward the total synthesis of (+)-providencin

    Creator:
    Jana, Somnath
    Abstract:
    Studies toward the total synthesis of (+)-providencin (1), a highly oxygenated cembranoid dipterpene with a unique bicyclo[12.2.0]hexadecane skeleton and pronounced biological activity, are described. These studies resulted in the synthesis of advanced intermediates 320 and 332 which contain all of the carbon atoms of 1. In a first generation approach...
    Resource Type:
    Dissertation
    Full Text:
    approved: _____________________________________________________ James D. White Studies toward

  • Tandem intramolecular photocycloaddition-retro-Mannich fragmentation as a route to indole and oxindole

    Creator:
    Li, Yang
    Abstract:
    Irradiation of a tryptamine linked through its side-chain nitrogen to an alkylidene malonate residue results in an intramolecular [2 + 2] cycloaddition to the indole 2,3-double bond. The resultant cyclobutane undergoes spontaneous retro-Mannich fission to produce a spiro[indoline-3,3-pyrrolenine] with relative configuration defined by the orientation of substituents in the transient...
    Resource Type:
    Dissertation
    Full Text:
    approved: James D. White

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

    Creator:
    Wang, Guoqiang
    Abstract:
    Studies towards the total synthesis of (-)-gymnodimine (1), a marine neurotoxin with a unique molecular architecture and pronounced biological activity, are described. These studies resulted in a convergent approach to the advanced intermediate 315, containing the C3-C32 section of 1. Two synthetic routes were developed to construct the tetrahydrofuran subunit...
    Resource Type:
    Dissertation
    Full Text:
    Total Synthesis of ()-Gvmnodimine Abstract James D. White Studies towards the total synthesis of

  • Asymmetric synthesis of cyclopropanes via a "zipper reaction"

    Creator:
    Lincoln, Christopher M.
    Abstract:
    The rearrangement of a homoallyl cation to a cyclopropylcarbinyl cation is thought to play a role in the biogenesis of a variety of cyclopropane-containing natural products,¹ a hypothesis which has previously led to the design of successful biomimetic syntheses of several natural products.² The strategy underlying this approach to cyclopropane...
    Resource Type:
    Dissertation
    Full Text:
    Synthesis of Cyclopropanes via a "Zipper Reaction" Abstract approved: James D. White The rearrangement of

  • 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:
    AN ABSTRACT OF THE DISSERTATION OF Kurt F. Sundermann for the

  • Synthesis of furanoeremophilane sesquiterpenoids

    Creator:
    Shanmugham, Meenakshi Sundaram
    Abstract:
    Two approaches to the tricyclic core of the furanoeremophilane sesquiterpenoids are described. The first approach entails a projected Diels-Alder/retro Diels-Alder reaction of an acetylenic oxazole 64. Construction of the pivotal aldehyde 67 commenced from ketone 68. The acetyenic moiety was then introduced via a Felkin-Ahn addition of lithiopropyne to aldehyde...
    Resource Type:
    Dissertation
    Full Text:
    FURANOEREMOPHILANE SESQUITERPENOIDS Abstract approved: James D. White Two approaches to the tricyclic core of the

  • 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
    Full Text:
    TOTAL SYNTHESIS OF PHORBOXAZOLE A. Abstract approved: James D. White Studies toward the total

  • Total synthesis of indole alkaloids: pt. 1. Asymmetric synthesis of (-)-ibogamine. pt. 2. An approach toward the synthesis of koumine

    Creator:
    Choi, Younggi
    Abstract:
    PART I. The preparation of (-)-ibogamine (1) in fourteen steps from benzoquinone and in 10% overall yield is a powerful illustration of the value of the asymmetric Diels-Alder reaction as a starting point in a multistep synthesis. All four cycloadducts, 70, 77, 84 and 96, obtained with the (S)-BINOL-TiCl₂ complex...
    Resource Type:
    Dissertation
    Full Text:
    SYNTHESIS OF KOUMINE. Abstracted approved: James D. White PART I. The preparation of ()-ibogamine (1) in