X-Ray study of (αS,SS/αR,SR)-1-(p-bromophenyl)ethyl t-butyl sulphoxide and conformational analysis of diastereoisomeric pairs of 1-phenylethyl t-butyl sulphoxides

Abstract

The title compound, C₁₂H₁₇BrOS, is monoclinic, space group P2₁/n, a= 12.87(1), b= 6.005(6), c= 17.32(2)Å, β= 90.37°Z= 4, D_m= 1.434 g cm^–3. The structure was solved by the heavy-atom method and refined to an R value of 0.09. It has been shown that the bulkiest group (Bu^t) orients itself anti to the methyl group and gauche to the phenyl group. Solution phenomena (n.m.r. and o.r.d.–c.d. data) of some diastereoisomeric pairs of 1-phenylethyl t-butyl sulphoxides are best interpreted by assuming that the predominant conformations of these molecules resemble those found in X-ray crystallographic studies.