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Filtering by: Creator Maciel, A. K. A. Remove constraint Creator: Maciel, A. K. A. Advisor White, James D. Remove constraint Advisor: White, James D.

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  • An approach toward the synthesis of euonyminol and cathedulin K- 19

    Creator:
    Shin, Hyunik
    Abstract:
    A synthetic approach toward the two major fragments of cathedulin K-19, euonyminol (4) and dimethyl cathate (69), was investigated. Synthesis of dimethyl cathate was accomplished in 3 steps starting from 73. Efforts directed towards the synthesis of euonyminol, a highly oxygenated dihydroagarofuran sesquiterpene, was advanced to a stage in which...
    Resource Type:
    Dissertation
    Full Text:
    Cathedulin K-19. Abstract approved by: A synthetic approach toward the two major fragments of cathedulin K

  • Synthesis of marine natural products. part I, Cryptophycins-1, -3, -4, -24, and -29, part II, Polycavernoside A

    Creator:
    Robarge, Lonnie A.
    Resource Type:
    Dissertation
    Full Text:
    , -3, -4, -24, and -29, part II, Polycavernoside A. AN ABSTRACT OF THE DISSERTATION OF Lonnie A

  • 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:
    . (b) Smith III, A. B.; Verhoest, P. R.; Minbiole, K. P.; Schelhaas, M. J. Am. Chem. Soc. 2001, 123

  • 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:
    , 9, 631. 23. Williams, D.R.; Shamim, K. Org. Lett. 2005, 7, 4161. 24. a) White, J.D.; Johnson

  • 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:
    exponent takes the form: -2m2[ h2a*2U11 + + 2 h k a* b* U'2

  • 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:
    K-Selectride as the hydride source. The resulting alcohol was protected as a tert

  • 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:
    Title: Studies Toward the Total Synthesis of Sanglifehrin A. Abstract approved

  • Approaches toward the asymmetric synthesis of pillaromycin A

    Creator:
    Nolen, Ernest G.
    Resource Type:
    Dissertation
    Full Text:
    A AN ABSTRACT OF THE THESIS OF Ernest G. Nolen Jr. for the degree of Doctor of Philosophy in

  • 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
    Full Text:
    The isolation and structure of leptosphaerin : a metabolite

  • 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:
    .; Nicholson, A. A.; Tchir, M. F. Can. J. Chem. 1969, 47, 711. 8. (a) Kearns, D. R.; Marsh, G.; Schaffner, K