Question

Describe the action of hydroiodic acid on the following :

(1) Diethyl ether.

(2) Ethyl methyl ether.

(3) Methyl n-propyl ether.

(4) Methyl phenyl ether (anisole).

Answer 1

(1) Diethyl ether :

When diethyl ether (ethoxy ethane) is treated with hydroiodic acid, a mixture of ethanol and ethyl iodide is formed.

If excess of hydroiodic acid is available, then ethyl alcohol further reacts with hydroiodic acid at higher temperature to form ethyl iodide and water.

(2) Ethyl methyl ether :

When ethyl methyl (methoxy ethane) is treated with hydroiodic acid, a mixture of ethyl alcohol and methyl iodide is formed.

If excess of hydroiodic acid is available, then ethyl alcohol further reacts with hydroiodic acid at higher temperature to form ethyl iodide and water.

(3) Methyl n-propyl ether :

When methyl n-propyl ether (1-Methoxy propane) is treated with hydroiodic acid, a mixture of n-propyl alcohol and methyl iodide is formed.

If excess of hydroiodic acid is available then npropyl alcohol further reacts with hydroiodic acid at higher temperature to form n-propyl iodide and water.

(4) Methyl phenyl ether (anisole) :

When methyl phenyl ether (anisole) is treated with hydroiodic acid, phenol and methyl iodide is formed. Here, phenol does not react further with HI because – OH group is attached to sp² -hybridised carbon atom and it cannot be replaced by iodide (nucleophile).