Stereoselective Direct Glycosylation with Anomeric Hydroxy Sugars by Activation with Phthalic Anhydride and Trifluoromethanesulfonic Anhydride Involving Glycosyl Phthalate Intermediates
作者:Kwan Soo Kim、Dinanath Baburao Fulse、Ju Yuel Baek、Bo-Young Lee、Heung Bae Jeon
DOI:10.1021/ja710935z
日期:2008.7.1
by sequential addition of DTBMP and Tf2O and glycosyl acceptors to the reaction mixture at -78 degrees C in one-pot. Stereoselective alpha-glucopyranosylations with 2,3-di-O-benzyl-4,6-O-benzylidene-D-glucopyranose (25) and other glycosylations with glucopyranoses and mannopyranoses having tetra-O-benzyl- and tetra-O-benzoyl protecting groups were also possible by utilizing the present one-pot glycosylation
A novel glycosylation procedure has been developed, featuring extremely low cost as well as experimental and environmental advantages. It is based on the direct activation of per-O-acetylated (or benzoylated) sugars by 5 mol % of cheap and eco-friendly methanesulfonic acid, under air in the absence of any solvent. Several products, including non-trivial glycosides and disaccharides, can be quickly