Stereoselective glycosylation of beta-sulfornium ions

CARB 38

Jin Park, ppoghost@uga.edu1, Jin Hwan Kim1, and Geert-Jan Boons, gjboons@ccrc.uga.edu2. (1) Department of Chemistry, University of Georgia, Complex Carbohydrate Research Center, 315 riverbend road, athens, GA 30602, (2) Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602
Despite recent advances in synthetic carbohydrate chemistry, efficient and high throughput synthesis of oligosaccharides remains a challenge. We have found that the addition of PhSEt to TMSOTf promoted glycosylations of trichloroacetimidates having an azido moiety at C-2, results in significant improvements of alfa anomeric-selectivities. Detailed NMR studies have shown that these glycosylations proceed through a beta-sulfonium ion intermediate, which upon displacement by sugar alcohol provide predominant alfa-glycosides.
 

General Posters
6:00 PM-8:00 PM, Tuesday, 28 March 2006 Georgia World Congress Center -- Ex. Hall B4, Poster

Division of Carbohydrate Chemistry

The 231st ACS National Meeting, Atlanta, GA, March 26-30, 2006