New approach to the synthesis of C-glycosides, azasugars, and aza C-glycosides | Posted on:1997-03-15 | Degree:Ph.D | Type:Thesis | University:Purdue University | Candidate:Gizaw, Yonas | Full Text:PDF | GTID:2464390014483178 | Subject:Chemistry | Abstract/Summary: | | Synthesis of sugar analogs in which the ring oxygen atom has been replaced by an-NR-group (azasugars) and/or the anomeric hydroxyl group has been replaced by a carbon atom (C-glycosides) has been a subject of intensive research interest in recent years. Many members of both classes of compounds are specific inhibitors of glycosidases, including enzymes involved in glycoprotein processing, glycogenolysis, and oligo- and disaccharide hydrolysis. In spite of recent developments in the synthesis of C-glycosides and azasugars, the stereospecific formation C-glycosides and aza C-glycosides remains a challenge for synthetic carbohydrate chemistry. A simple way to prepare C-glycosides and aza C-glycosides of D-arabinose and D-lyxose, that can be applied to other aldoses, is reported. The reaction involves oxidation of D-glucose diethyl dithioacetal (with spontaneous cyclization) to the corresponding ({dollar}alpha{dollar}-D-arabinopyranosyl)-di(ethyl sufonyl)methane. Reduction to the diethyl dithioacetal of ({dollar}alpha{dollar}-D arabinosyl) formaldehyde, and converting it to an aldhehyde provides a compound which can be modified to other desired products. Oxidation of a protected 6-amino-6-deoxy-D-galactose diethyl dithioacetal provided the corresponding azasugars. | Keywords/Search Tags: | Azasugars, C-glycosides, Diethyl dithioacetal | | Related items |
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