Which one of the following compounds can exist as cis-trans isomers?

• A

  Pent-1-ene
• B

  2-Methylhex-2-ene
• C

  1, 1-Dimethylcyclopropane
• Correct answer
  D

  1, 2-Dimethylcyclohexane

Solution

For GI in alkene, each terminal individually must have different atoms/groups attached to it. For GI in cyclo-alkane, at least two $\mathrm{sp}^3 \mathrm{C}$ of ring individually must have different atoms/groups attached to it.

Hence, the correct answer is option: 'D'.