Stereoselective reactions in carbohydrate synthesis
This thesis deals with two topics connected with carbohydrate chemistry. The first part presents epoxidation and dihydroxylation reactions of glycals using Mo-catalysts and m-chloroperbenzoic acid (MCPBA) towards the synthesis of manno oligosaccharides. The oxidation of glycals afforded in all cases...
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| Format: | doctoral thesis |
| Status: | Published version |
| Publication Date: | 2012 |
| Country: | España |
| Institution: | Universitat Rovira i virgili (URV) |
| Repository: | Repositori Institucional de la Universitat Rovira i Virgili |
| OAI Identifier: | oai:urv.cat:TDX:1036 |
| Online Access: | https://hdl.handle.net/20.500.11797/TDX1036 http://hdl.handle.net/10803/76720 |
| Access Level: | Open access |
| Keyword: | 547 - Química orgànica |
| Summary: | This thesis deals with two topics connected with carbohydrate chemistry. The first part presents epoxidation and dihydroxylation reactions of glycals using Mo-catalysts and m-chloroperbenzoic acid (MCPBA) towards the synthesis of manno oligosaccharides. The oxidation of glycals afforded in all cases the corresponding diols or glycosides, as a consequence of the in situ opening of the epoxides initially formed. Free hydroxyl groups were observed to direct the stereoselectivity of the epoxidation, and then manno derivatives were obtained from unprotected or partially protected glucals. The results using Mo-catalysts are among the best described for the catalytic epoxidation of glycals. The results using MCPBA were excellent, and this methodology was applied to the synthesis of orthogonally protected glycosyl donors. The second part is related to the synthesis of the cardiotonic digitoxin. Two different strategies were studied in order to obtain 2-deoxy-glycosides through olefination-cyclization-glycosylation reaction and using asymmetric synthesis. |
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