UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Efforts towards syntheses of marine natural products Loosley, Benjamin Charles

Abstract

This thesis describes work attempting to synthesize and derivatize marine natural products. Chapter 1 outlines a brief history of natural products chemistry. It explains why modern medicines are commonly derived from natural sources using historical examples. It also explains why natural products chemists have turned to organisms in the oceans for exploration into new and unique molecular frameworks and biological activities. Chapter 2 describes the work done towards total synthesis of the marine natural product cladoniamide G. The successful approach involves coupling a halogenated 2,2-bisindole with an unsymmetric, tricarbonyl electrophile. It also describes work towards synthesis of analogues, including attempts to glycosylate the natural product. Chapter 3 is the first chapter that discusses work towards total synthesis of a second marine natural product, nahuoic acid A. This chapter focuses on synthesis of a linear cycloaddition precursor that resembles an intermediate in the presumed biosynthetic pathway. The work in this chapter culminates in attempts at a Diels-Alder reaction to form a cis-decalin system. Chapter 4 also focuses on work towards total synthesis of nahuoic acid A. However, the work in this chapter uses a Diels-Alder reaction to form a cis-decalin system early, and then focuses on the challenges of functionalizing the decalin. Four general approaches to functionalization are investigated: conjugate additions, nucleophilic substitutions, sigmatropic rearrangements, and metal catalyzed cycloisomerizations.

Item Citations and Data

Rights

Attribution-NonCommercial-NoDerivatives 4.0 International