title: Towards novel difluorinated sugar mimetics; syntheses and conformational analyses of highly-functionalised difluorinated cyclooctenones.
abstract: Highly-functionalised difluorinated cyclooctenones were synthesised from trifluoroethanol using either metallated difluoroenol acetal or carbamate chemistry, followed by a [2,3]-Wittig rearrangement or aldol reaction. Efficient RCM reactions afforded the title compounds which showed rather restricted fluxional behaviour by VT (19)F NMR. Topological characterisation by molecular modelling and NOESY/ROESY experiments offered a number of challenges, but allowed the identification of two favoured boat-chair conformers which interconverted by pseudorotation with relatively large activation barriers.
authors: Department of Chemistry, University of Leicester, University Road, Leicester, UK LE1 7RH.
authors: Gerry A
authors: GA
authors: Griffith
authors: Jonathan M
authors: JM
authors: Percy
authors: Stéphane
authors: S
authors: Pintat
authors: Clive A
authors: CA
authors: Smith
authors: Neil
authors: N
authors: Spencer
authors: Emi
authors: E
authors: Uneyama
mesh_terms: D002241:Carbohydrates / Q000737:chemistry*; D005461:Fluorine / Q000737:chemistry*; D006841:Hydrocarbons, Aromatic / Q000138:chemical synthesis* / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D018716:Molecular Mimicry; D016339:Spectrometry, Mass, Fast Atom Bombardment
chemical_list: D002241:Carbohydrates; D006841:Hydrocarbons, Aromatic; D005461:Fluorine