Towards the Total Synthesis of 1α,25-dihydroxylumisterol
Author(s)
Partridge, Alan
Type
Thesis
Abstract
This thesis is divided into three chapters.
The first chapter provides a brief review on recent work in the application of cascade
cyclisations to the total synthesis of natural products. This is followed by a review of
the decarboxylative Claisen rearrangement (dCr), a novel variant of the
Ireland-Claisen reaction in which tosylacetic esters of allylic alcohols are transformed
into homoallylic sulfones using BSA and potassium acetate, and its applications.
The second chapter discusses the results of our studies towards the total synthesis of
1α,25-dihydroxylumisterol via a proposed route containing two key steps; a
cascade-inspired, Lewis-acid mediated cyclisation to form the steroid B-ring in I, and
the dCr reaction of tosylacetic ester IV to give diene III. Successful syntheses, as
well as problems encountered along this route will be discussed, as well as the
measures taken to adapt the synthesis to circumvent these problems [Molecular structure diagrams appear here. To view, please open pdf attachment].
The third and final chapter contains experimental procedures and characterisation
data for the prepared compounds.
The first chapter provides a brief review on recent work in the application of cascade
cyclisations to the total synthesis of natural products. This is followed by a review of
the decarboxylative Claisen rearrangement (dCr), a novel variant of the
Ireland-Claisen reaction in which tosylacetic esters of allylic alcohols are transformed
into homoallylic sulfones using BSA and potassium acetate, and its applications.
The second chapter discusses the results of our studies towards the total synthesis of
1α,25-dihydroxylumisterol via a proposed route containing two key steps; a
cascade-inspired, Lewis-acid mediated cyclisation to form the steroid B-ring in I, and
the dCr reaction of tosylacetic ester IV to give diene III. Successful syntheses, as
well as problems encountered along this route will be discussed, as well as the
measures taken to adapt the synthesis to circumvent these problems [Molecular structure diagrams appear here. To view, please open pdf attachment].
The third and final chapter contains experimental procedures and characterisation
data for the prepared compounds.
Date Issued
2012-09
Date Awarded
2013-03
Copyright Statement
Attribution NoDerivatives 4.0 International Licence (CC BY-ND)
Advisor
Craig, Donald
Publisher Department
Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)