α-Selective glycosylation with β-glycosyl sulfonium ions prepared via intramolecular alkylation

<none>

Programme Social programme Plenary speakers Keynote speakers 1st EuroCarb Young Researcher (ECYR) Workshop CarboMet Workshop Mini symposium: Glycobiology at the LUMC and beyond Favourites/Agenda

Social programme

Plenary speakers

Keynote speakers

1st EuroCarb Young Researcher (ECYR) Workshop

CarboMet Workshop

Mini symposium: Glycobiology at the LUMC and beyond

Favourites/Agenda

Photos

Venue & Travel Venue Accommodation City of Leiden Travel directions

Venue

Accommodation

City of Leiden

Travel directions

Committees

Home

α-Selective glycosylation with β-glycosyl sulfonium ions prepared via intramolecular alkylation

Sam Moons 1 , Rens Mensink 1 , Jeroen Bruekers 1 , Maurits Vercammen 1 , Laura Jansen 1 , Thomas Boltje 1

1 Radboud University Nijmegen, Nijmegen, The Netherlands

The major challenge in the chemical synthesis of oligosaccharides is the stereoselective synthesis of the glycosidic bond. 1,2-trans glycosides can be synthesized with high selectivity by the use of neighboring group participation of a C-2 acyl group and is applicable to gluco- and manno-type sugars. In contrast, the stereoselective synthesis of 1,2-cis glycosides remains more challenging. By utilizing neighboring group participation using C-2 chiral auxiliaries, the stereoselective synthesis of 1,2-cis gluco[1]- and manno[2]-type sugars could be achieved. These reactions proceed via an intermediate sulfonium ion, which is depicted in scheme 1. This intermediate can be prepared by making three disconnections, of which two have already been explored[1,3].

Using a thioglycoside precursor, β-sulfonium ion intermediates could by prepared utilizing an unexplored disconnection. The synthetic route to this glycoside donors allows for a late stage introduction of the C-2 auxiliary, giving more control over the outcome of the stereoselectivity using a single glycosyl donor. Using low-temperature NMR studies, the activation of the glycosyl donor, as well as the formation of the β-sulfonium ion were investigated. Subsequently, the influence of the thioaryl moiety, as well as the benzyl protecting groups on the stereoselectivity was explored.

J.-H. Kim, H. Yang, J. Park, G.-J. Boons, J. Am. Chem. Soc. 2005, 127, 12090-12097.

Elferink, H.; Mensink, R. A.; White, P. B.; Boltje, T. J. Angew. Chem.,Int.Ed.2016, 55, 11217−11220

M. A. Fascione, S. J. Adshead, S. A. Stalford, C. A. Kilner, A. G. Leach, W. B. Turnbull, Chem. Commun. 2009, 5841-5843

Contact eurocarb@eurocarb2019.com for general questions about EUROCARB2019, or codee@eurocarb2019.com for scientific questions.

Leiden University / Leiden Institute of Chemistry lic.leidenuniv.nl

European Carbohydrate Organisation

Congress by Design www.congressbydesign.com