White Rose University Consortium logo
University of Leeds logo University of Sheffield logo York University logo

Novel Approaches Toward the Synthesis of Pseudaminic Acid

Fields, Alexander Matthew (2019) Novel Approaches Toward the Synthesis of Pseudaminic Acid. PhD thesis, University of Sheffield.

[img] Text (Thesis)
Restricted until 20 May 2024.

Request a copy


Pseudaminic acid is a carbohydrate glycoside which is found on post-translationally glycosylated bacterial flagella. Disturbance of the biosynthetic pathway for this sugar nullifies the pathogenicity of the bacteria A. caviae, H. pylori & C. jejuni. In order to explore this possibility, attempts were made to develop a novel synthetic route. Parallel to efforts to synthesis the side chain of pseudaminic acid, L-allo-threonine, N-chiral imines derived from cheap and readily available (2S)-ethyl lactate were prepared and subjected to Lewis acid-mediated trimethylsilylcyanide additions as part of new methodology for robust and facile asymmetric Strecker reactions. 2,3-anti¬-β-Hydroxy-α-aminonitriles were prepared in excellent yield (77%, 4 steps) and good diastereoselectivity (90 : 10). L-allo-threonine was accessed and further functionalised to Garner-like cyclic aldehydes which were used as substrates for a doubly diastereoselective nitroaldol reaction to construct the carbon chain of pseudaminic acid. These reactions proceeded with mild selectivity and conversion. Models for the addition to both Garner aldehydes and N-chiral imines were discussed in detail.

Item Type: Thesis (PhD)
Academic Units: The University of Sheffield > Faculty of Science (Sheffield) > Chemistry (Sheffield)
Depositing User: Mr AM Fields
Date Deposited: 28 May 2019 09:14
Last Modified: 28 May 2019 09:14
URI: http://etheses.whiterose.ac.uk/id/eprint/24051

Please use the 'Request a copy' link(s) above to request this thesis. This will be sent directly to someone who may authorise access.
You can contact us about this thesis. If you need to make a general enquiry, please see the Contact us page.

Actions (repository staff only: login required)