Question

What is ‘X’ in the following reaction?
2–Bromo–2–methyl butane $\xrightarrow{X}$ 2–methyl–2–butanol

• A. CH$_2$Cl$_2$
• B. CH$_3$CN
• C. (CH$_3$)$_2$N–CHO
• D. H$_2$O

Hint:

Tertiary alkyl halides react with water via SN1 mechanism to form tertiary alcohols.

Answer 1

The Correct Option is D

2–Bromo–2–methylbutane is a tertiary alkyl halide. When it is treated with water (H$_2$O), it undergoes nucleophilic substitution (SN1 mechanism) to form the corresponding alcohol — 2–methyl–2–butanol. Water acts as the nucleophile and replaces the bromine atom with a hydroxyl group (–OH).

Answer 2

What is ‘X’ in the following reaction?

2–Bromo–2–methylbutane → X → 2–methyl–2–butanol

Step 1: Analyze the reaction type:
The reaction involves conversion of an alkyl halide (2–Bromo–2–methylbutane) to an alcohol (2–methyl–2–butanol).
This is a typical nucleophilic substitution reaction (SN1 type) where the halide (Br⁻) is replaced by a hydroxyl group (OH⁻).

Step 2: Suitable reagent for substitution:
Since the compound is tertiary (due to the 2-methyl-2-butyl structure), SN1 mechanism is favored.
Thus, the reaction proceeds with water (H₂O) as the nucleophile under mild conditions.

Therefore, the correct reagent X is:
\[ \boxed{\textbf{H}_2\textbf{O}} \]