[(1S,2S,3R,4R)-3-Hydr­oxy-4,7,7-tri­methyl­bicyclo­[2.2.1]heptan-2-yl]methyl[(E)-3-(trimethyl­silyl)prop-2-enyl]selen­onium bromide

The title compound, a seleno­nium bromide, C(17)H(33)OSeSi(+)·Br(−), was obtained from the reaction of enanti­omerically pure 4,7,7-trimethyl-2-methyl­selanylbicyclo­[2.2.1]heptan-3-ol and (3-bromopropen­yl)trimethyl­silane in acetone. Due to the chiral bicyclic substituent, the crystal structure is not centrosymmetric and has no symmetry plane, with four chiral C atoms in the cation. The asymmetric unit contains one seleno­nium cation and one bromide anion. C–H⋯Br and O–H⋯Br hydrogen bonds link the ions, forming a one-dimensional R-helical chain-like supra­molecular structure.