Question
Explain the preparation of ethers with mech$-$anism by dehydration of alcohols.
✓
Answer
$\rightarrow$ Alcohols undergo dehydration in the presence of protic acids $\ce{(H_2SO_4, H_3PO_4)}.$ The formation of the reaction product, alkene or ether depends on the reaction conditions. For example, ethanol is dehydrated to ethene in the presence of sul$-$phuric acid at $443 K.$ At $413 K,$ ethoxyethane is the main product.
$\rightarrow$ The formation of ether is a nucleophilic bimolecular reaction $(S_N2)$ involving the attack of alcohol molecule on a protonated alcohol, as indicated below:
$(iii)$
$\rightarrow$ Acidic dehydration of alcohols, to give an alkene is also associated with substitution reaction to give an ether.
$\rightarrow$ The formation of ether is a nucleophilic bimolecular reaction $(S_N2)$ involving the attack of alcohol molecule on a protonated alcohol, as indicated below:
$(iii)$
$\rightarrow$ Acidic dehydration of alcohols, to give an alkene is also associated with substitution reaction to give an ether.
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