Isomerism · Question 38

[figure] obtained by chlorination of n-butane will be

1. meso form
2. racemic mixture
3. d-form
4. l-form

Answer

(2) racemic mixture

Solution

Chlorination of n-butane is a free radical substitution.

Cl removes an H atom from C-2, giving the planar (sp2) radical CH3-CH2- CH-CH3.

Cl2 attacks this planar radical from either face with equal probability.

(+)- and (–)-2-chlorobutane are formed in equal amounts, i.e. a racemic mixture (optically inactive).

Answer: (2)