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Filtering by: Creator Marshall, Nicole S. Remove constraint Creator: Marshall, Nicole S. Advisor White, James D. Remove constraint Advisor: White, James D. Degree Level Doctoral Remove constraint Degree Level: Doctoral

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  • Absolute stereochemistry and total synthesis of botryococcene

    Creator:
    Reddy, Guvvala Nagabhushana
    Abstract:
    Studies were carried out to determine the absolute stereochemistry of botryococcene (1). The natural product was degraded to two sets of 'y- and 8- valerolactones. All enantiomeric variations of these lactones were synthesized in optically pure form starting from (S)- and (R)-methyloxiranes. 1H NMR correlation of natural and synthetic materials...
    Resource Type:
    Dissertation
    Full Text:
    pure form starting from (S)- and (R)-methyloxiranes. 1H NMR correlation of natural and synthetic

  • 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
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    1990’s and early 2000’s, the Marshall group was one of the key contributors to synthetic efforts

  • Synthetic studies of nonadrides

    Creator:
    Drapela, Nicholas Ernest
    Abstract:
    An asymmetric approach to the synthesis of byssochlamic acid (1) is described. Regioisomeric enzymatic differentiation is described in the selective hydrolysis of dimethyl ester 30 by porcine liver esterase. Chiral dimethyl ester 42 was prepared by desymmetrization of cyclopentene 34 using porcine liver esterase. A key intramolecular [2+2]cycloaddition-cycloreversion photometathesis of...
    Resource Type:
    Dissertation
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    . The carboxylate salts of 42 with (R)- and (S)-phenethylamine were made (Scheme 9), but formed poorly

  • 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
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    of (R)- and (S)- MTPA esters of 166…….. 1H NMR Spectra of Synthetic (a) and Natural (b

  • The total synthesis of (-)- acorenone B ; Approaches to the synthesis of mycosporin (P 310)

    Creator:
    Ruppert, John Fredrick
    Resource Type:
    Dissertation
    Full Text:
    -lactone 42. Hydrogenation of 42 over Adams s catalyst followed by hydrogenolysis over palladium-on

  • Approaches to the synthesis of penicillin

    Creator:
    Furuta, Takuya
    Abstract:
    Several approaches to the synthesis of penicillin from 2-iminothioazolidine 50, from 2-thiothiazolidine 66 and by photocyclization of 77 and 78 were investigated. 2-Iminothiazolidine 50 was prepared from dibromoester 45 by the action of benzylamine followed by treatment of aziridine 46 with potassium or ammonium thiocyanate. Attempted introduction of a two-carbon...
    Resource Type:
    Dissertation
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    S 1 HN COOH HOOC 13 HN COOH 0 4 t-BuO0C 9 CHO 7 Ac 20/60° HC1 H2O COOH NaOAc /H20

  • 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
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    defects.3 It was later discovered that only the (S)- enantiomer of the drug is teratogenic. Since that

  • 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
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    cyclohexenone with 1 -bromo- 3-butene led to (S)-6-(3-butenyl)cyclohex-2-enone (59) after removal of the

  • Approaches to the synthesis of trichothecane sesquiterpenes

    Creator:
    Thomas, James Anthony
    Resource Type:
    Dissertation
    Full Text:
    underwent elimina- tion to the a,S-unsaturated ester 35, and, in a truly unique step, 30 was obtained upon

  • The synthesis of trisporic acids

    Creator:
    Prisbylla, Michael Paul
    Abstract:
    A total synthesis of the fungal hormones, trisporic acids A and B, is described, starting from a -methyltetronic acid 34. A Robinson annelation of 34 with ethyl vinyl ketone affords the lactone 33. Treatment of 33 with N-bromosuccinimide gave 97, which was hydrolyzed to the lactol 103. The reaction of...
    Resource Type:
    Dissertation
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    lactone does appear to give 37 upon addition of s odium hydroxide (by thin layer chromatography), but