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 19F 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.
- difluorinated cyclooctenones
- difluorinated sugar mimetics
Percy, J. M., Griffith, G. A., Pintat, S., Smith, C. A., Spencer, N., & Uneyama, E. (2005). Towards novel difluorinated sugar mimetrics; syntheses and conformational analyses of highly-functionalised difluorinated cyclooctenones. Organic and Biomolecular Chemistry, 3, 2701-2712. https://doi.org/10.1039/B505978J