Synthetic approaches to the cladiellin diterpenes

Hewitt, Natalie L. 2015. Synthetic approaches to the cladiellin diterpenes. PhD Thesis, Cardiff University. Item availability restricted.

Preview	PDF - Accepted Post-Print Version Download (18MB) | Preview
	PDF - Supplemental Material Restricted to Repository staff only Download (959kB)

Abstract

This thesis describes the result of synthetic efforts to apply a novel desymmetrisation process to the cladiellin diterpenes, an important group of natural products. The aim is to use the novel Prins-Wagner-Meerwein desymmetrisation of cyclohexa-1,4-dienes to prepare octahydroisobenzofuran structures that are closely related to the cladiellin diterpenes. Chapter 1 presents a short review of the 2,11-cyclised cembranoids including the cladiellin diterpene structures and previous synthetic efforts, followed by a brief discussion of the Prins cyclisation. This is followed by a description of previous work carried out within the Elliott group on the Prins desymmetrisation of cyclohexa-1,4-dienes that sets the stage for the work described in chapters 2 – 5. Chapter 2 describes the alkylation of cyclohexa-1,4-dienes using n-BuLi and TMEDA to give a direct and highly diastereoselective route to the corresponding 4-substituted products in which the alkyl group introduced is trans to the carboxylic acid. Chapter 3 describes the attempted application of Prins cyclisation/rearrangement methodology to the core of the cladiellin diterpenes. This was successful for a model compound containing a 6-membered ring, but when applied to compounds containing 7- and 9-membered rings, macrocyclic dimeric products were obtained. Chapter 4 describes an alternative synthetic strategy from that attempted in Chapter 3, to construct the cladiellin diterpene framework using a 6,5-fused system and cleaving of this to give a 9-membered ring system. Chapter 5 describes the successful synthesis of a model compound containing a fused aromatic ring using the strategy developed in Chapter 4.

Item Type:	Thesis (PhD)
Status:	Unpublished
Schools:	Chemistry
Subjects:	Q Science > QD Chemistry
Uncontrolled Keywords:	Cladiellin diterpenes; Natural products; 2,11-cyclised cembranoids; Cyclohexa-1,4-dienes; Prins-Wagner-Meerwein desymmetrisation; Octahydroisobenzofuran; Alkylation
Funders:	EPSRC, AstraZeneca
Date of First Compliant Deposit:	30 March 2016
Last Modified:	10 Aug 2016 01:30
URI:	https://orca.cardiff.ac.uk/id/eprint/74997

Actions (repository staff only)

Edit Item