Conformation and stereodynamics of alkyl 9-anthryl sulfoxides

Abstract

Several alkyl 9-anthryl sulfoxides exhibit broadening of the aromatic peri-proton signal in ¹H NMR spectra recorded at ambient temperature due to hindered rotation about the 9-anthryl–sulfur bond; the rotational barriers lie in the range 10.9–18.9 kcal mol^–1. The preferred conformation and torsional barriers in these sulfoxides and in mesityl methyl sulfoxide have also been investigated by molecular mechanics calculations.