Conformational analysis, stereoelectronic interactions and NMR properties of 2-fluorobicyclo[2.2.1]heptan-7-ols

Beilstein J Org Chem. 2012:8:1227-32. doi: 10.3762/bjoc.8.137. Epub 2012 Aug 2.

Abstract

Four diastereoisomers of 2-fluorobicyclo[2.2.1]heptan-7-ols were computationally investigated by using quantum-chemical calculations, and their relative energies were analyzed on the basis of stereoelectronic interactions, particularly the presence or otherwise of the F∙∙∙HO intramolecular hydrogen bond in the syn-exo isomer. It was found through NBO and AIM analyses that such an interaction contributes to structural stabilization and that the (1h)J(F,H(O)) coupling constant in the syn-exo isomer is modulated by the n(F)→σ*(OH) interaction, i.e., the quantum nature of the F∙∙∙HO hydrogen bond.

Keywords: 1hJF,H(O) coupling constant; 2-fluorobicyclo[2.2.1]heptan-7-ols; conformational analysis; hydrogen bond; quantum-chemical calculations.