Question

Diethyl ether when refluxed with excess of HI gives two molecules of (i). Ethers can be most commonly prepared by reaction of (ii) and (iii) . The method is called (iv).
(i), (ii),(iii) and (iv) respectively are?

• A. ethyl iodide, sodium alkoxide , alkyl halide, Williamson's synthesis
• B. ethanol, alcohol , alkyl halide , substitution
• C. methyl iodide, Grignard's reagent , alkyl halide , Williamson's synthesis
• D. ethyl iodide, phenol, ethyl iodide, esterification

Answer 1

The correct option is A ethyl iodide, sodium alkoxide , alkyl halide, Williamson's synthesis

When ethers are treated with strong acid in the presence of a nucleophile, they can be cleaved to give alcohols and alkyl halides. If the ether is on a primary carbon this may occur through an $S_{N}2$ pathway.

Thus Diethyl ether ($C_2{H}_{5}O{C}_2{H}_5$) when refluxed with Hi gives two molecules as $C_2{H}_{5}I+NaO{C}_2{H}_5$. And in excess of HI, the alkoxide undergoes subtitution reaction and gives alkyl halide as $C_2{H}_{5}I$

Thus (i)=$C_2{H}_{5}I$.

Ethers can be most commonly prepared by Williamson's synthesis where a reaction of alkyl halide and sodium alkoxide takes place. Therefore (ii) and (iii) are alkyl halide and sodium alkoxide. The method is called Williamson's synthesis=(iv)

(i), (ii),(iii) and (iv) respectively are $C_2{H}_{5}I$, alkyl halide, sodium alkoxide and Williamson's synthesis, respectively.