• Libraries
    • Log in to:
    View Item 
    •   MSpace Home
    • Faculty of Graduate Studies (Electronic Theses and Practica)
    • FGS - Electronic Theses and Practica
    • View Item
    •   MSpace Home
    • Faculty of Graduate Studies (Electronic Theses and Practica)
    • FGS - Electronic Theses and Practica
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    The synthesis of enantiomerically pure aryltetralin lignans

    Thumbnail
    View/Open
    nq23581.pdf (15.76Mb)
    Date
    1997-09-11
    Author
    Bogucki, David E.
    Metadata
    Show full item record
    Abstract
    The preparation of enantiomerically pure aryltetralin lignans has been accomplished using both a Diels-Alder approach and a newer oxidative free radical coupling/cyclization. Past research established that aryltetralins could be asymmetrically prepared by a Diels-Alder reaction of $\alpha$-hydroxy-$\alpha$-phenyl-ortho-quinodimethane with a chiral dienophile. In this thesis, the previous preliminary work was extended to the preparation of a cycloadduct that was further elaborated to the natural lignan ($-$)-deoxy-podophyllotoxin. In the latter steps, an unprecedented stereoselective ionic reduction was developed. In the pursuit of an even more efficient method for the synthesis of aryltetralin lignans, new stereoselective Diels-Alder reactions of ortho-quinodimethanes were investigated. Substituted chiral crotonate esters were successfully reacted with $\alpha$-hydroxy-ortho-quinodimethane and found to diastereoselectively give only one cycloadduct in high yield. A new approach to the synthesis of aryltetralin lignans involving the oxidative coupling of substituted chiral cinnamic acid esters was studied. It was discovered that the chiral methyl ($R$)-mandelyl group would induce diastereoselectivity in the oxidative coupling/cyclization of its sinapic acid ester, forming the diester of the naturally occurring lignan thomasidioic acid. This unprecedented stereoselective reaction was used to prepare (+)-rabdosiin and its ($-$)-$(1R,2S)$-isomer, the enantiomers of which are natural anti-viral lignans.
    URI
    http://hdl.handle.net/1993/777
    Collections
    • FGS - Electronic Theses and Practica [25494]

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV
     

     

    Browse

    All of MSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    Login

    Statistics

    View Usage Statistics

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV