Conformation and absolute configuration of 2‐naphthylalkylsulfoxides by combined use of dynamic NMR, ECD spectroscopy, DFT computations, and X‐ray diffraction

Abstract

The E/Z conformer ratios of five 2-naphtylalkylsulfoxides were determined by means of dynamic NMR spectroscopy at very low temperatures and this information was used to predict, by means of DFT calculations, the ECD spectra of the R and S enantiomers. The latter were separated by enantioselective HPLC technique and the comparison of theoretical and experimental ECD spectra allowed the absolute configurations to be determined. In the case of 2-naphtyl tert-butylsulfoxide (1), the assignment was independently confirmed by anomalous dispersion using single crystal X-ray crystallography.