Use this URL to cite or link to this record in EThOS: | https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.523271 |
![]() |
|||||||
Title: | New sulfone-assisted strategies for alkaloid synthesis | ||||||
Author: | Tholen, Niels T. H. |
ISNI:
0000 0004 2693 870X
|
|||||
Awarding Body: | Imperial College London | ||||||
Current Institution: | Imperial College London | ||||||
Date of Award: | 2010 | ||||||
Availability of Full Text: |
|
||||||
Abstract: | |||||||
This thesis is divided into three chapters. Chapter 1 provides brief reviews on the subjects of previous total syntheses of suaveoline, alstonerine and cytisine. In addition, a review concerning the Pictet–Spengler reaction mechanism and its application to the total syntheses of isoquinoline containing natural products has been included as well. Chapter 2 focuses on the research findings in the past three years. Two routes were investigated towards the total synthesis of (±)-suaveoline involving the decarboxylative Claisen rearrangement (dCr), N-sulfonylaziridine chemistry and subsequent nucleophilic ringopening of the latter by various sulfone-anions. Route A focused on the use of oxo-lithio chelation during aziridine ring-opening while route B employed selective weakening of the aziridine C–N bond proximal to the olefin by PiC–C→Sigma* C–N overlap (Scheme 0.1). Attempts towards total synthesis of (±)-alstonerine involved the preparation and subsequent screening of various sulfone-anions against the indolic hydroxy aziridine, followed by an interesting E1cB / Michael addition, cis-Pictet–Spengler cyclization and an ambitious global reduction step. Furthermore progress towards total synthesis of (–)-cytisine involved investigation towards the application of regioselective sulfone-anion hydroxy-aziridine opening mediated by oxolithio- chelation. Chapter 3 provides the experimental details and characterization data.
|
|||||||
Supervisor: | Craig, Donald | Sponsor: | Not available | ||||
Qualification Name: | Thesis (Ph.D.) | Qualification Level: | Doctoral | ||||
EThOS ID: | uk.bl.ethos.523271 | DOI: | |||||
Share: |