title: Aqueous Glycosylation of Unprotected Sucrose Employing Glycosyl Fluorides in the Presence of Calcium Ion and Trimethylamine.
abstract: We report a synthetic glycosylation reaction between sucrosyl acceptors and glycosyl fluoride donors to yield the derived trisaccharides. This reaction proceeds at room temperature in an aqueous solvent mixture. Calcium salts and a tertiary amine base promote the reaction with high site-selectivity for either the 3'-position or 1'-position of the fructofuranoside unit. Because nonenzymatic aqueous oligosaccharide syntheses are underdeveloped, mechanistic studies were carried out in order to identify the origin of the selectivity, which we hypothesized was related to the structure of the hydroxyl group array in sucrose. The solution conformation of various monodeoxysucrose analogs revealed the co-operative nature of the hydroxyl groups in mediating both this aqueous glycosyl bond-forming reaction and the site-selectivity at the same time.
authors: Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520-8107, United States.
authors: Guillaume
authors: G
authors: Pelletier
authors: Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520-8107, United States.
authors: Aaron
authors: A
authors: Zwicker
authors: Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520-8107, United States.
authors: C Liana
authors: CL
authors: Allen
authors: Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520-8107, United States.
authors: Alanna
authors: A
authors: Schepartz
authors: Department of Chemistry, Yale University , 225 Prospect Street, New Haven, Connecticut 06520-8107, United States.
authors: Scott J
authors: SJ
authors: Miller
mesh_terms: D002118:Calcium / Q000737:chemistry*; D006031:Glycosylation; D008744:Methylamines / Q000737:chemistry*; D013395:Sucrose / Q000737:chemistry*; D014312:Trisaccharides / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D008744:Methylamines; D014312:Trisaccharides; D013395:Sucrose; C023336:trimethylamine; D002118:Calcium