DISSABS / 2006:21112

AN

    2006:21112  DISSABS   Order Number: AAI3185209

TI

    ROMP approaches for organic synthesis and efforts toward the synthesis of
    cyclipostins

AU

    Poon, Wing Cheong [Ph.D.]; Hanson, Paul R. [advisor]

CS

    The University of Kansas (0099)

SO

    Dissertation Abstracts International, (2004) Vol. 66, No. 8B, p. 4231.
    Order No.: AAI3185209. 155 pages. 
    ISBN: 0-542-26785-3.

DT

    Dissertation

FS

    DAI

LA

    English

ED

    Entered STN: 20060428
    Last Updated on STN: 20060428

AB

         The work reported herein describes the applications of ring-opening
    metathesis polymerization (ROMP) using well-defined ruthenium-based
    catalysts for organic synthesis, and efforts toward the synthesis of
    cyclipostins.
         A strategy to synthesize oligomeric sulfonamides employed both
    ring-closing metathesis (RCM) and ring-opening metathesis polymerization
    (ROMP). Amino acid-derived cyclic sulfonamides containing either exocyclic
    or γ-endocyclic stereogenic centers were generated via RCM. These
    cyclic sulfonamides underwent stereoselective Diels-Alder reactions to
    yield endo-norbornenyl sulfonamides as major diastereomers. Subsequent
    ROMP rapidly produced sulfonamide-based oligomers, and these oligomers
    exhibited different solubility in a variety of solvents. Based on the
    solubility difference of these oligomers, a capture-ROMP-release strategy
    for the chromatography-free purification of Mitsunobu reaction products is
    described. Oxo-norbornenyl-tagged reagents are utilized for standard
    solution phase Mitsunobu chemistry. Post-reaction, phase-switching was
    accomplished via in situ ROMP followed by precipitation of the polymer
    with methanol. Release of the product from the polymer afforded amines and
    alkyl hydrazine derivatives with good yields and purities.
         The C-H activation strategy mediated by Rh2(OAc)4 was utilized toward
    the synthesis of cyclipostins. This novel class of natural product
    possesses strong inhibitory action against hormone-sensitive lipase
    (HSL) and has potential in the development of therapeutic agents to
    regulate lipolysis for the treatment of noninsulin-dependent diabetes
    mellitus (NIDDM). The initial results of this project are reported.

CC

    0490 CHEMISTRY, ORGANIC; 0487 CHEMISTRY, BIOCHEMISTRY