What will be the major product when m-cresol is reacted with propargyl bromide ($\mathrm{HC} \equiv \mathrm{C} -\mathrm{CH}_{2} \mathrm{Br}$) in presence of $\mathrm{K}_{2} \mathrm{CO}_{3}$ in acetone

JEE Main · 2019 · 12 Apr 2019 · Shift 2 · Alcohols Phenols and Ethers

What will be the major product when m-cresol is reacted with propargyl bromide (

HC \equiv C - CH_{2} Br

) in presence of

K_{2} CO_{3}

in acetone

Answer: (C)

With the mild base

K X_{2} CO X_{3}

, the phenolic

- OH

of m-cresol is deprotonated to a phenoxide, a good nucleophile. It attacks the

CH X_{2}

carbon of propargyl bromide in a Williamson ether synthesis, displacing bromide. The product is the O-propargyl ether of m-cresol,

CH X_{3} - C X_{6} H X_{4} - O - CH X_{2} - C \equiv CH

, with alkylation occurring on oxygen rather than on the ring.

JEE Main · 2019 · 12 Apr 2019 · Shift 2 · Single correct option