6-[4-( tert -Butyl-dimethyl-sil-yloxy)phen-yl]-1-oxa-spiro-[2.5]hepta-ne.

The title compound, C 19 H 30 O 2 Si, has triclinic ( P ) symmetry at 100 K. The O atom of the epoxide group has a pseudoaxial orientation and the dihedral angle between the cyclo-hexyl and benzene rings is 85.80 (8)°. The C-O-Si-C t ( t = tert -but-yl) torsion angle is -177.40 (14)°. In the crystal, pairwise C-H⋯O links connect the mol-ecules into inversion dimers featuring R 2 2 (8) loops.