Question

Which of the following will have meso-isomer ?

• A. 2- chlorobutane
• B. 2- hydroxyopanoic acid
• C. 2, 3- dichloropentane
• D. 2, 3- dichlorobutane

Answer 1

The correct option is D 2, 3- dichlorobutane

Mesomer is a stereoisomer which is optically inactive due to the presence of any element of symmetry in the molecule.
In the given compounds, 2, 3-dichlorobutane has a plane of symmetry which leads to a mesomer.
The structure of mesomer is shown below,


Other compound (a), (b) and (c) didn't have any element of symmetry so they don't have a mesomer.