When ethers are exposed to atmospheric oxygen and light for extended periods, they slowly autoxidize — Alcohols Phenols and Ethers Chemistry Question

💡 Solution & Explanation

Ethers undergo slow free-radical autoxidation at the $\alpha$ -carbon to form highly unstable and explosive hydroperoxides. Their presence is detected by shaking the ether with an aqueous solution of ferrous ammonium sulfate ($Fe^{2+}$) and $KSCN$. The peroxides oxidize $Fe^{2+}$ to $Fe^{3+}$, which then coordinates with thiocyanate ($SCN^-$) to form a characteristic blood-red complex.