Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.657301
Title: Application of nitrile oxide/isoxazoline chemistry in C-glycoside synthesis
Author: March, Andrew Ronald
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 2000
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Abstract:
A route to C-glycosides and C-disaccharides with functionalised linkages has been investigated. This convergent strategy involves cycloaddition of selected alkenes and sugar derived nitrile oxide moieties. The resultant 2-isoxazolines can be modified and subsequently ring opened to afford compounds with carbonyl or amino containing linkages. The alkenes selected for study were two w-unsaturated monosaccharide derivatives: 5,6-dideoxy-1,2-O-isopropylidene-a-D-xylo-hex-5-enofuranose and methyl 5,6-dideoxy-2,3-O-isopropylidene-a-D-lyxo-hex-5-enofuranoside. Styrene, oct-1-ene and methylenecyclohexane were also studied as models. Four sugar based nitrile oxides were investigated in cycloadditions to these alkenes, based on D-glucose, D-galactose, D-mannose and L-fucose. Three complementary cycloaddition procedures were developed and evaluated: the dehydration of 2,6-anhydro-1-deoxy-1-nitroalditols, the hypochlorite-mediated oxidative dehydrogenation of pyranosyl oximes, and the dehydrochlorination of a pyranosyl hydroximoyl chloride. The oximes and hydroximoyl chloride compounds were synthesised from the corresponding pyranosylnitromethanes. Reactions involving the sugar oximes typically resulted in variable yields of the by-product furazan N-oxide (furoxan) in addition to the cycloadducts, depending on the dipolarophile reactivity. In contrast, uniformly high yields of cycloadducts (70-90%) were obtained from the nitromethyl compounds and hydroximoyl chloride with a range of dipolarophiles; little or no nitrile oxide dimerisation was observed in these reactions.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.657301  DOI: Not available
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