Silva, Thayna F. B. published the artcileEndocyclic Oxygen in 3-Fluorodihydro-2H-pyran-4(3H)-one That Does Not Induce the Gauche Effect, Related Products of tetrahydropyran, the publication is Journal of Physical Chemistry A (2014), 118(32), 6266-6271, database is CAplus and MEDLINE.
2-Fluorocyclohexanone undergoes chair inversion, giving rise to axial and equatorial conformers, with the equatorial form being highly preferred in solution, for example, 87% in chloroform and 93% in methylene chloride. Modifications in the conformational preferences can modify macroscopic properties of 2-fluoro ketones. The introduction of an endocyclic oxygen in 2-fluorocyclohexanone to give 3-fluorodihydro-2H-pyran-4(3H)-one would be expected to create a gauche effect in the axial conformer along with the O-C-C-F moiety, inducing an increase of its population. However, small changes were verified in the conformational populations both in the gas phase and solution because the carbonyl group plays an important role for the hyperconjugation in the equatorial conformer, despite experiencing strong dipolar repulsion with the fluorine atom. These data were obtained theor. and by NMR spectroscopy, while the nature of the interactions governing these conformational shifts were investigated on the basis of natural bond orbital anal.
Journal of Physical Chemistry A published new progress about 624734-19-6. 624734-19-6 belongs to tetrahydropyran, auxiliary class Tetrahydropyran,Fluoride,Ketone, name is 3-Fluorodihydro-2H-pyran-4(3H)-one, and the molecular formula is C10H16Br3N, Related Products of tetrahydropyran.
Referemce:
https://en.wikipedia.org/wiki/Tetrahydropyran,
Tetrahydropyran – an overview | ScienceDirect Topics