Application of nitrile oxide/isoxazoline chemistry in C-glycoside synthesis
A route to <i>C</i>-glycosides and <i>C</i>-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 subsequ...
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ndltd-bl.uk-oai-ethos.bl.uk-6573012016-04-25T15:18:54ZApplication of nitrile oxide/isoxazoline chemistry in C-glycoside synthesisMarch, Andrew Ronald2000A route to <i>C</i>-glycosides and <i>C</i>-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-<i>O</i>-isopropylidene-a-D-<i>xylo</i>-hex-5-enofuranose and methyl 5,6-dideoxy-2,3-<i>O</i>-isopropylidene-a-D-<i>lyxo</i>-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.547.78University of Edinburghhttp://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.657301http://hdl.handle.net/1842/12565Electronic Thesis or Dissertation |
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547.78 March, Andrew Ronald Application of nitrile oxide/isoxazoline chemistry in C-glycoside synthesis |
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A route to <i>C</i>-glycosides and <i>C</i>-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-<i>O</i>-isopropylidene-a-D-<i>xylo</i>-hex-5-enofuranose and methyl 5,6-dideoxy-2,3-<i>O</i>-isopropylidene-a-D-<i>lyxo</i>-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. |
author |
March, Andrew Ronald |
author_facet |
March, Andrew Ronald |
author_sort |
March, Andrew Ronald |
title |
Application of nitrile oxide/isoxazoline chemistry in C-glycoside synthesis |
title_short |
Application of nitrile oxide/isoxazoline chemistry in C-glycoside synthesis |
title_full |
Application of nitrile oxide/isoxazoline chemistry in C-glycoside synthesis |
title_fullStr |
Application of nitrile oxide/isoxazoline chemistry in C-glycoside synthesis |
title_full_unstemmed |
Application of nitrile oxide/isoxazoline chemistry in C-glycoside synthesis |
title_sort |
application of nitrile oxide/isoxazoline chemistry in c-glycoside synthesis |
publisher |
University of Edinburgh |
publishDate |
2000 |
url |
http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.657301 |
work_keys_str_mv |
AT marchandrewronald applicationofnitrileoxideisoxazolinechemistryincglycosidesynthesis |
_version_ |
1718234942369955840 |