Molecular conformations. Part VIII. The bicyclo[2,2,2]octane system: X-ray analysis of 1-p-bromobenzenesulphonyloxymethylbicyclo[2,2,2]-octane

Abstract

The conformation of a 1-p-bromobenzenesulphonyloxymethyl derivative of bicyclo[2,2,2]octane has been determined by a single-crystal X-ray analysis. The crystals are monoclinic, space group P2₁/c, with four molecules of C₁₅H₁₉SO₃Br in a unit cell of dimensions a 18·99, b 6·65, c 12·56 Å, β 96·0°. The structure was solved by the heavy-atom method and refined by least-squares methods. R is 0·104 for 1715 data. The bicyclo[2,2,2]octyl system closely conforms to symmetry D₃, with the group of atoms C(2)C(7)C(6) rotated 3° about the C(1)⋯ C(4) axis with respect to the C(3)C(5)C(8) group. This has the effect of increasing the torsional angles at C(2)–C(3), C(5)–C(6), and C(7)–C(8) to 5°, whereas with an eclipsed D_3h model a zero value would hold.