Question:

Write the products of the following reaction : \[ (CH_3)_3C-O-C_2H_5 \xrightarrow{HI} ? \]

Show Hint

In ether cleavage by HI, if one alkyl group is tertiary, cleavage occurs at the tertiary carbon through the \(S_N1\) pathway because tertiary carbocations are highly stable.
Updated On: Jun 29, 2026
Show Solution
collegedunia
Verified By Collegedunia

Solution and Explanation

Concept: Ethers undergo cleavage in the presence of concentrated hydrogen halides such as HI and HBr. The reaction proceeds through protonation of the ether oxygen followed by cleavage of the carbon--oxygen bond. The nature of the alkyl groups attached to oxygen determines the mechanism of cleavage. When one of the groups attached to oxygen is tertiary, cleavage generally occurs through the \(S_N1\) mechanism because tertiary carbocations are highly stable.

Step 1: Identify the ether The given ether is: \[ (CH_3)_3C-O-C_2H_5 \] This compound is tert-butyl ethyl ether. One side contains a tertiary alkyl group while the other side contains a primary ethyl group.

Step 2: Protonation of oxygen The oxygen atom first accepts a proton from HI. \[ (CH_3)_3C-O-C_2H_5 + H^+ \rightarrow (CH_3)_3C-OH^+-C_2H_5 \] This weakens the carbon--oxygen bond.

Step 3: Formation of tertiary carbocation The bond breaks preferentially at the tertiary carbon because a tertiary carbocation is highly stable. \[ (CH_3)_3C^+ + C_2H_5OH \]

Step 4: Attack by iodide ion The tertiary carbocation combines with iodide ion. \[ (CH_3)_3C^+ + I^- \rightarrow (CH_3)_3CI \]

Step 5: Final products Thus the products formed are: \[ (CH_3)_3CI \] and \[ C_2H_5OH \] \[ \boxed{ (CH_3)_3C-O-C_2H_5 + HI \rightarrow (CH_3)_3CI + C_2H_5OH } \]

Final Answer \[ \boxed{ (CH_3)_3CI + C_2H_5OH } \]
Was this answer helpful?
0
0

Top CBSE CLASS XII Chemistry Questions

View More Questions