Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.552335
Title: Synthesis studies to single stereoisomers of the vicinal trifluoroalkane motif
Author: Brunet, Vincent
Awarding Body: University of St Andrews
Current Institution: University of St Andrews
Date of Award: 2009
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Abstract:
This thesis focuses on the construction of individual isomers of the R-CHF-CHF-CHF-R’ motif. The multi-vicinal fluorine motif is new in organic chemistry and therefore stereoselective methods giving rapid access to these motifs and with flexibility need to be explored. The research in the thesis succeeded in the preparation of (2S,3R,4S)-314 and (2S,3S,4R)-328. In Chapter 1, an overview of the impact of fluorine in organic molecules is given. Recent developments in asymmetric electrophilic and nucleophilic fluorination are described, as well as the preparation of multivicinal fluoroalkane motifs. Aldol reactions of either (R)- or (S)-N-(α-fluoropropyl)-2-oxazolidinones, mediated by TiCl 4 are reported in Chapter 2. Such aldol reactions gave rise to identical α-fluoro-β-hydroxy- aldol products with high diastereoselectivities (95% dr). After removal from the auxiliary α- fluoro-β-hydroxy- products were converted to the corresponding α,β-difluoro products. The synthesis of non symmetric vicinal trifluoro motifs (2S,3R,4S)-314 and (2S,3S,4R)-328 is described in Chapter 3. They were prepared by direct fluorination in three steps of the corresponding (2R,3R,4R)-erythro and (2R,3S,4S)-threo enantio-enriched epoxy-alcohols. The two erythro and threo epoxy-alcohol isomers behave very differently during the first fluorination step and then an attempt to study and rationalise this difference in behaviour is made.
Supervisor: O'Hagan, David Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.552335  DOI: Not available
Keywords: QD412.F1B88 ; Organofluorine compounds--Synthesis ; Stereoisomers
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