Efficient Carbohydrate Synthesis By Intra- and Supramolecular Control
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
The Lattrell-Dax method of nitrite-mediated substitution of carbohydrate triflates is an efficient method to generate structures of inverse configuration. In this study, the effects of the neighboring group on the Lattrell-Dax inversion were explored. A new carbohydrate/anion host-guest system was discovered and the ambident reactivity of the nitrite anion was found to cause a complicated behavior of the reaction. It has been demonstrated that a neighboring equatorial ester group plays a highly important role in this carbohydrate epimerization reaction, restricting the nitrite N-attack, thus resulting in O-attack only and inducing the formation of inversion compounds in good yields. Based on this effect, efficient synthetic routes to a range of carbohydrate structures, notably β-D-mannosides and β-D-talosides, were designed by use of double parallel and double serial inversion. A supramolecularly activated, triggered cascade reaction was also developed. This cascade reaction is triggered by a deprotonation process that is activated by anions. It was found that the anions can activate this reaction following their hydrogen bonding tendencies to the hydroxyl group in aprotic solvents.
Place, publisher, year, edition, pages
Stockholm: KTH , 2009. , 59 p.
Trita-CHE-Report, ISSN 1654-1081 ; 2009:2
Carbohydrate Chemistry, Supramolecular Control, Ambident Reactivity
IdentifiersURN: urn:nbn:se:kth:diva-9882ISBN: 978-91-7415-207-4OAI: oai:DiVA.org:kth-9882DiVA: diva2:139802
2009-02-05, F3, KTH, Lindstedtsvägen 26, Stockholm, 10:00 (English)
Nilsson, Ulf, Docent
Ramström, Olof, Docent
QC 201007092009-01-272009-01-262012-02-23Bibliographically approved
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