Alcohols and Ethers - Result Question 3
####4. The major product of the following reaction is
(2019 Main, 9 April I)
(a)
(c)
(b)
(a)
(c)
(b)
(d)
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Answer:
Correct Answer: 4. (a)
Solution:
- Key Idea $PBr _3$ reagent is used for the substitution of $-Br$ group while alc. $KOH$ reagent is used to carry out elimination reaction.
The given reaction proceed in following manner:
Step I In presence of $PBr _3$, alcohols undergo substitution reactions to give halides. Reagent $PBr _3$ is usually generated insitu by the reaction of red phosphorus with bromine.
Step II 3-bromohexanone in presence of alc. $KOH$ undergoes elimination reaction and gives cyclohex-2-en-1-one.
