Graduation Year

2004

Document Type

Thesis

Degree

M.S.

Degree Granting Department

Chemistry

Major Professor

Kyung Woon Jung

Keywords

Tetrahydroisoquinoline, Heterocycle, Isoquinolone, Ecteinascidin, Praziquantel

Abstract

The thesis is composed of three chapters. The aim of this thesis is to apply the novel dirhodium perfluorobutyrate-catalyzed intramolecular aromatic C-H insertion methodology to the enantioselective total synthesis of praziquantel and synthetic model studies on ecteinascidin 743, which belongs to the important tetrahydroisoquinoline family. The first introductory chapter deals with the biological significance and previous synthetic methodologies. Our novel methodology is based on dirhodium perfluorobutyrate-catalyzed intromolecular aromatic C-H insertion reaction, which is crucial in the pivotal carbon-carbon bond formation when constructing isoquinolone moiety, which is ubiquitous in numerous natural products of significant biological and pharmacological activities. The second chapter takes on the first enantioselective total synthesis of praziquantel, an antihelmintic drug.

Praziquantel is used worldwide to treat schistosomiasis, which has tremendous impact on the global fight on this disease affecting 150 million people. We believe this is the first asymmetric total synthesis to date, which is distinct from previous racemic syntheses reported. We also shed light on the mechanistic aspect of this key reaction to rationalize the superb regioselectivity and stereoselectivity achieved. The third chapter explores the synthetic model studies on ecteinascidin 743, a tetrahydroisoquinolone family natural product with significant antitumor and antimicrobial activities. Several different synthetic routes were attempted, including the N-Methyl and the N-Boc routes, and the results achieved contributed significantly to our final synthetic plan of the target molecule.

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