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  • Synthetic studies n bioactive natural products. Part I, An approach towards the nootrophic agent huperzine A. Part II, Synthesis of the tricarbonyl subunit of rapamycin

    Creator:
    Jeffrey, Scott C.
    Resource Type:
    Dissertation
    Full Text:
    rapamycin AN ABSTRACT OF THE DISSERTATION OF Scott C. Jeffrey for the degree of Doctor of Philosophy in

  • 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:
    , Professor Rich G. Carter, Professor Paul R. Blakemore, Professor Kevin P. Gable, Professor Janet Tate and

  • 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:
    produced by this method in high enantiomeric excess. This protocol was used to synthesize (R)-Montelukast

  • 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:
    ] photocycloaddition to the total synthesis of natural products. Inter- as well as O O O O O R O R O R R R

  • 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

  • Approaches to the synthesis of polyketides. Vermiculine

    Creator:
    Kirkemo, Curtis Lee
    Abstract:
    An approach to the generation of polyketides was investigated, which involved ozonolysis of 6, 7 cyclopenteno -1> 4, 5, 8 -tetrahydromethoxy- 3-methylnaphthalene (26), to produce what is believed to be polyketide 27. Compound 26 was formed by the following sequence: Die ls -Alder addition of 1, 2 -dim.ethylenecyclopentane and 2...
    Resource Type:
    Dissertation
    Full Text:
    and A.I. Scott (9) con- structs masked polyketide systems with the P-diketone units protected in the

  • 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
    Full Text:
    . RI-IN RI-IN R -CO( CH 2 ) 3 CH COOH NH 2 2 C 00H CH OA c 2 Two major problems arose after

  • 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
    Full Text:
    Acid 5: Heveadride 3: Glaucanic Acid 6: Castaneiolide O 7a: Rubratoxin A (R = H, OH) 7b

  • 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:
    , Nick Drapela, Uwe Grether, Roger Hanselmann, Josh Hansen, Bryan Hauser, David IhIe, Scott Kemp, Linda

  • 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:
    , Paul R. Blakemore, Cindy Browder, Rich G. Carter, Bobby Chow, Jorg Deerberg, Nicholas E. Drapela, Uwe