Question

Which of the following does not contain plane symmetry?

• A. trans-1,3-dichloro cyclohexane
• B. trans-1,2-dichloro cyclohexane
• C. cis-1,2-dichloro cyclohexane
• D. trans-1,3-cyclopentane

Hint:

Cis–disubstitution on cyclohexane often removes symmetry due to axial–equatorial positions.

Answer 1

The Correct Option is C

Step 1: Plane of symmetry divides a molecule into two identical halves. Step 2: \beginitemize • trans-1,2 and trans-1,3 substituted cyclohexanes possess symmetry. • cis-1,2-dichloro cyclohexane has no plane of symmetry due to asymmetric axial–equatorial arrangement. \enditemize Step 3: Hence, cis-1,2-dichloro cyclohexane does not contain plane symmetry.