Chemical Properties of Ethers

1. Classification: Chemical properties of ethers are classified mainly into reactions involving cleavage of the C–O bond.

2. C–O Bond Cleavage Reactions:

• R–O–R + HX (100°C) → R–OH + R–X
• R–O–R′ + PCl₅ (Δ) → R–Cl + R′–Cl
• R–O–R′ + H₂O (dil. H₂SO₄, pressure) → R–OH + R′–OH
• R–O–R + R′COCl (AlCl₃/ZnCl₂, Δ) → R–Cl + R′COOR
• R–O–R + (R′CO)₂O (AlCl₃/ZnCl₂, Δ) → 2 R′COOR

3. Reactivity order of HX with ethers: HI > HBr > HCl.

4. Preparation of Diethyl Ether:

• 2 C₂H₅OH → C₂H₅–O–C₂H₅ (conc. H₂SO₄/H₃PO₄, 413 K)
• C₂H₅ONa + BrCH₂CH₃ → C₂H₅–O–C₂H₅ (Williamson's synthesis, Δ)

5. Reactions of Diethyl Ether:

• O₂ (long contact) → Peroxide of diethyl ether
• dil. H₂SO₄ → 2 C₂H₅OH
• PCl₅ (Δ) → C₂H₅OH + C₂H₅Cl
• Hot HI → C₂H₅I + C₂H₅OH
• HI (excess) → 2 C₂H₅I