Chemistry - STEREO ISOMERISM Question with Solution | TestHub

Ans. (B) S₄.

Sol. In this 1,3,5,7-tetrabromo-2,4,6,8-tetramethylcyclooctane, a rotation of 90 degrees about the axis through the ring centre followed by reflection in the ring plane maps each Br onto the next Br and each CH₃ onto the next CH₃ with wedge and dash interchanged exactly as drawn : an S₄ improper axis. There is no plane of symmetry and no S₂ (inversion centre) or S₆ axis.