erythro -{1-Bromo-1-[(1-phenyl-eth-yl)sulfon-yl]eth-yl}benzene.

The title compound, C 16 H 17 BrO 2 S, crystallizes as the erythro ( RR/SS ) isomer of a pair of sulfones that were diastereomeric due to chirality of the α-carbon atoms on the sulfone sulfur atom. The structural analysis was pivotal in showing that the 1,3 elimination reactions of these compounds, which lead to substituted stilbenes, occur with inversion at each asymmetric carbon atom. In the crystal, C-H⋯Br and C-H⋯O hydrogen bonds link the mol-ecules into a tri-periodic inter-molecular network.