Question

Which of the following will have a meso isomer also.

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

Answer 1

The correct option is B

2, 3-dichlorobutane

Explanation of the correct option:

(B) 2, 3-Dichlorobutane

• The compound has two similar asymmetric $\mathrm{C}-$atoms.
• It has a plane of symmetry and exists in meso form.

Explanation of incorrect options:

(A) 2-Hydroxipropanoic acid

• The compound contains an achiral center at the ${\mathrm{C}}_2$ position.
• The compound does not contain the two or more stereocenters and therefore, the 2-Hydroxipropanoic acid is not a meso compound.

(C) 2, 3-Dichloropentane

• 2, 3-Dichloropentane contains two stereocenters at ${\mathrm{C}}_2$ and ${\mathrm{C}}_3$ carbon atom.
• The compound does not contain the internal plane symmetry.
• Therefore 2, 3-Dichloropentane is not a meso compound.

(D) 2-Chlorobutane

• This compound does not possess the internal plane of symmetry.
• The chlorine is present at $2$ number Carbon position.
• This prevent the formation of the meso compound.

Hence, option (B) is correct., 2, 3-Dichlorobutane will have a meso isomer.