title: Access to tetrachlorophthalimide-protected ethyl 2-amino-2-deoxy-1-thio-beta-D-glucopyranosides.
abstract: Ethyl 2-deoxy-2-tetrachlorophthalimido-1-thio-beta-D-glucopyranoside (7) was prepared from glucosamine hydrochloride in four steps with a 20-25% overall yield. Formation of 1,3,4,6-tetra-O-acetyl-2-deoxy-2-tetrachlorophthalimido-beta-D- glucopyranoside (5) was found to be crucial for this reaction sequence since the corresponding alpha-1-acetate did not react in Lewis-acid-catalyzed ethylthio glycosidations. Formation of the beta-1-acetate (5) was achieved by treatment of 3,4,6-tri-O-acetyl-2-deoxy-2-tetrachlorophthalimido-alpha-D-glucop yranosyl bromide (4) with acetic acid under silver zeolite promotion. This was necessary because conditions normally used for beta-1-acetate formation were not tolerated by the tetrachlorophthalimido (TCP) group.
authors.affiliation: Natural Products and Glycotechnology Research Institute, Durham, NC 27707, USA.
authors.forename: L
authors.initials: L
authors.lastname: Olsson
authors.forename: S
authors.initials: S
authors.lastname: Kelberlau
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Jia
authors.forename: B
authors.initials: B
authors.lastname: Fraser-Reid
mesh_terms: D002240:Carbohydrate Sequence; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D005944:Glucosamine / Q000031:analogs & derivatives*; D008956:Models, Chemical; D008969:Molecular Sequence Data; D010797:Phthalimides / Q000737:chemistry*; D013863:Thioglucosides / Q000737:chemistry*
chemical_list: D010797:Phthalimides; D013863:Thioglucosides; D005944:Glucosamine