Target Exam

CUET

Subject

Chemistry

Chapter

Organic: Haloalkanes and Haloarenes

Question:

Identify the product of the following reaction

Options:

$CH_3CH_2Br$

Correct Answer:

Explanation:

The correct answer is Option (3) →

 

Tertiary alkyl halides react with strong bases like ethoxide ion via elimination (E2) rather than substitution due to steric hindrance.

Detailed Explanation

Option 1: $CH_3CH_2O-C(CH_3)_3$

Ether formation would require SN2 substitution. However, tert-butyl bromide is highly hindered, making SN2 substitution difficult.

Option 2: $H_2C=CH_2$

Formation of ethene would require elimination from ethyl group, which is not present as substrate.

Option 3: $(CH_3)_2C=CH_2$

Ethoxide ion acts as a strong base and removes a ẞ-hydrogen from tert-butyl bromide leading to elimination via E2 mechanism.

Product formed is isobutene (2-methylpropene).

Option 4: $CH_3CH_2Br$

This would require substitution at ethoxide ion, which does not occur.