Question

Organic compound (P) $\xrightarrow{(i) \text{ excess of} HI, (ii) \text{ Aq. } NaOH} Q + R$. $Q$ and $R$ both gives Iodoform test, Which among the following is (P) from the given organic compound?

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

When an ether is cleaved by excess $\text{HI}$, it yields alkyl iodides, which are then hydrolyzed to corresponding alcohols. For both products to pass the iodoform test, both resultant alcohols must contain the $\text{R}-\text{CH}(\text{OH})\text{CH}_3$ functional group (where R can be H).

Answer 1

The Correct Option is C

Step 1: The given reaction involves ether cleavage using excess $HI$. Step 2: Ethers on treatment with excess $HI$ undergo cleavage to give alkyl iodides: \[ R-O-R' + HI \rightarrow RI + R'I \] Step 3: Alkyl iodides on treatment with aqueous $NaOH$ form alcohols: \[ RI + NaOH \rightarrow ROH \] Step 4: Both products $Q$ and $R$ give iodoform test, so both must contain: \[ R-CH(OH)-CH_3 \quad \text{or} \quad R-CO-CH_3 \] Step 5: Option (3) corresponds to ethyl–isopropyl ether: \[ CH_3CH_2-O-CH(CH_3)_2 \] Step 6: Cleavage gives: \[ CH_3CH_2OH \quad \text{and} \quad (CH_3)_2CHOH \] Step 7: Ethanol (special case) and isopropyl alcohol both give iodoform test. Hence, correct option is (3).