Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.581273
Title: Oxidative radical cyclisations for total synthesis
Author: Ferrara, Steven
Awarding Body: University of Oxford
Current Institution: University of Oxford
Date of Award: 2013
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Abstract:
Manganese(III) acetate mediated radical cyclisations provide a mild and powerful tool in the construction of complex bicyclic systems. This thesis focuses on the formation of a number of alkenyl substituted [3.3.0]-bicyclic γ-lactones utilising a manganese(III) acetate/copper(II) triflate induced radical cyclisation. The methodology was then applied to a short catalytic and enantioselective synthesis of (+)-aphanamol I and related natural products. Chapter 1 presents a summary of the theories and methodology which will be utilised in this work. In particular, a key focus will revolve around oxidative radical cyclisations and how manganese(III) acetate has become a vital oxidant in such areas. Chapter 2 details a catalytic and asymmetric total synthesis of (+)-aphanamol I. Following an overview of the natural product and its previous total synthesis, a racemic and asymmetric total synthesis is presented which utilises a manganese(III) acetate mediated radical cyclisation and a Claisen ring expansion as key steps. Chapter 3 reports the synthesis and subsequent cyclisation of a wide range of dienyl malonate substrates. Variation of the γ-substituent is first explored, demonstrating the effect that substituent size has on the diastereoselectivity of the cyclisation. Following this, the synthesis of [2.3.0]-,[4.3.0]- and [5.3.0]- bicyclic γ-lactones are investigated. Chapter 4 describes studies towards the total synthesis of a dolabellane natural product. Investigations into substrate synthesis which can be used in a RCM will be presented. Full experimental details and spectral data, with select NMR spectra are also provided.
Supervisor: Burton, Jonathan Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.581273  DOI: Not available
Keywords: Organic chemistry ; Organic synthesis ; Natural products ; Synthetic organic chemistry ; Radical chemistry ; manganese(III) acetate ; Aphanamol I ; Claisen ring expansion
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