Question

A mixed ether (P), when heated with excess of hot concentrated hydrogen iodide produces two different alkyl iodides which when treated with aq. NaOH give compounds (Q) and (R) give yellow precipitate with NaOI. Identify the mixed ether (P):

• A.
• B.
• C.
• D.

Hint:

Ethers cleave with HI to form alkyl iodides. Check the resulting alcohols for the methyl carbinol group for iodoform test.

Answer 1

The Correct Option is B

Reaction with HI cleaves ether into alkyl iodides. Hydrolysis gives alcohols.
Iodoform test (Yellow ppt with NaOI) is positive for alcohols with $CH_3-CH(OH)-$ group.
Option 2: Isopropyl sec-butyl ether.
Cleavage yields Isopropyl iodide ($CH_3CHICH_3$) and sec-butyl iodide ($CH_3CHICH_2CH_3$).
Hydrolysis gives Isopropyl alcohol (2-Propanol) and 2-Butanol.
Both 2-Propanol and 2-Butanol have the required group and give positive iodoform test.
Also, the ether is "mixed" (two different groups).