Alcohols and Ethers - Result Question 4
####6. The major product of the following reaction is
(2019 Main, 8 April I)
(a)
(c)
(b)
(d)
(a) $CH _3 CH _2 COCH _3+PhMgX$
(b) $PhCOCH _3+CH _3 CH _2 MgX$
(c) $PhCOCH _2 CH _3+CH _3 MgX$
(d) $HCHO+PhCH\left(CH _3\right) CH _2 MgX$
(2019 Main, 8 April I)
(2019 Main, 12 Jan I)
(d)
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Answer:
Correct Answer: 6. (b)
Solution:
- Key Idea Ethers are least reactive functional groups. The cleavage of $C-O$ bond in ethers take place under drastic conditions with excess of $H X$.
The major product obtained in the reaction is as follows :
As conc. HBr is in excess. So, reaction will take place at both the substituents.
Mechanism
Step 1 Protonation of ether to form oxonium ion.
Step 2 Attack of nucleophile at the protonated ether.
Step 3 As $HBr$ is in excess, so, reaction will also take place at alkene.
