title: 3,4,6-Tri-O-acetyl-1,2-O-[1-(exo-ethoxy)ethylidene]-β-D-mannopyranose 0.11-hydrate.
abstract: The title compound, C(16)H(24)O(10)·0.11H(2)O, is a key intermediate in the synthesis of 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG), which is the most widely used molecular-imaging probe for positron emission tomography (PET). The crystal structure has two independent molecules (A and B) in the asymmetric unit, with closely comparable geometries. The pyranose ring adopts a (4)C(1) conformation [Cremer-Pople puckering parameters: Q = 0.553 (2) Å, θ = 16.2 (2)° and φ = 290.4 (8)° for molecule A, and Q = 0.529 (2) Å, θ =15.3 (3)° and φ = 268.2 (9)° for molecule B], and the dioxolane ring adopts an envelope conformation. The chiral centre in the dioxolane ring, introduced during the synthesis of the compound, has an R configuration, with the ethoxy group exo to the mannopyranose ring. The asymmetric unit also contains one water molecule with a refined site-occupancy factor of 0.222 (8), which bridges between molecules A and B via O-H···O hydrogen bonds.
authors.affiliation: School of Chemical and Material Engineering, Jiangnan University, Wuxi, Jiangsu 214122, People's Republic of China.
authors.forename: Ya-Ling
authors.initials: YL
authors.lastname: Liu
authors.forename: Pei
authors.initials: P
authors.lastname: Zou
authors.forename: Hao
authors.initials: H
authors.lastname: Wu
authors.forename: Min-Hao
authors.initials: MH
authors.lastname: Xie
authors.forename: Shi-Neng
authors.initials: SN
authors.lastname: Luo
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008358:Mannose / Q000031:analogs & derivatives* / Q000737:chemistry; D008958:Models, Molecular; D009005:Monosaccharides / Q000737:chemistry*
chemical_list: C576494:3,4,6-tri-O-acetyl-1,2-O-(1-(exo-ethoxy)ethylidene)-beta-D-mannopyranose 0.11-hydrate; D009005:Monosaccharides; D008358:Mannose