title: Regioselective synthesis of 4azido-Neu2en5,7Ac(2)1Me and its intramolecular transformation to 4azido-Neu2en5,9Ac(2)1Me.
abstract: Methyl 5-N-acetyl-7-O-acetyl-4-azido-2,3-didehydro-2,4-dideoxy-neuraminic acid (4azido-Neu2en5,7 Ac(2)1Me) was synthesized regioselectively starting from 4azido-Neu2en5Ac1Me in high yield. The transformation of 4azido-Neu2en5,7Ac(2)1Me to the corresponding thermodynamically stable 4azido-Neu2en5,9Ac(2)1Me via intramolecular acetyl migration was confirmed by single-crystal X-ray diffraction analysis. The proposed rearrangement mechanism is discussed.
authors.affiliation: Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai 201203, PR China.
authors.forename: Qingjie
authors.initials: Q
authors.lastname: Zhao
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Lou
authors.forename: Ruisheng
authors.initials: R
authors.lastname: Xiong
authors.forename: Haihong
authors.initials: H
authors.lastname: Li
authors.forename: Jingshan
authors.initials: J
authors.lastname: Shen
mesh_terms: D002236:Carbohydrate Conformation; D002241:Carbohydrates / Q000138:chemical synthesis* / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006868:Hydrolysis; D008958:Models, Molecular; D019158:N-Acetylneuraminic Acid / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D002241:Carbohydrates; C533235:methyl 5-N-acetyl-7-O-acetyl-4-azido-2,3-didehydro-2,4-dideoxyneuraminic acid; C533236:methyl 5-acetamido-9-O-acetyl-2,6-anhydro-4-azido-3,4,5-trideoxy-glycero-galacto-non-2-enoic acid; D019158:N-Acetylneuraminic Acid