title: Differently N-protected 3,4,6-tri-O-acetyl-2-amino-2-deoxy-D-glucopyranosyl chlorides and their application in the synthesis of diosgenyl 2-amino-2-deoxy-β-D-glucopyranoside.
abstract: Four differently N-protected 3,4,6-tri-O-acetyl-2-amino-2-deoxy-d-glucopyranosyl chlorides were synthesized and used as glycosyl donors in reactions with diosgenin. The following amine group protections were tested: trifluoroacetyl (TFA), 2,2,2-trichloroethoxycarbonyl (Troc), phthaloyl (Phth), and tetrachlorophthaloyl (TCP). Products of glycosylation were deprotected to yield diosgenyl 2-amino-2-deoxy-β-d-glucopyranoside. The efficiency of the procedures is discussed. Additionally, a single-crystal X-ray diffraction analysis for 3,4,6-tri-O-acetyl-2-deoxy-2-tetrachlorophthalimido-β-d-glucopyranosyl chloride is reported. Orientations of the pyranose substituents as well as the planarity of the acetoxy and phthalimide groups in the crystal lattice are discussed. Structural evidence is presented for a mesomeric effect in both groups. The preference of the cis over trans orientation of the acetoxy group is confirmed in the crystal lattice.
authors.affiliation: Faculty of Chemistry, University of Gdańsk, J. Sobieskiego 18, PL-80-952 Gdańsk, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Bednarczyk
authors.forename: Agata
authors.initials: A
authors.lastname: Walczewska
authors.forename: Daria
authors.initials: D
authors.lastname: Grzywacz
authors.forename: Artur
authors.initials: A
authors.lastname: Sikorski
authors.forename: Beata
authors.initials: B
authors.lastname: Liberek
authors.forename: Henryk
authors.initials: H
authors.lastname: Myszka
mesh_terms: D002240:Carbohydrate Sequence; D004144:Diosgenin / Q000138:chemical synthesis* / Q000737:chemistry*; D008969:Molecular Sequence Data; D012503:Saponins / Q000138:chemical synthesis* / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D012503:Saponins; C420652:diosgenyl 2-amino-2-deoxy-glucopyranoside; D004144:Diosgenin