Question

Identify the major product formed in the following reaction:

• A. 1
• B. 2
• C. 3
• D. 4

Hint:

A Grignard reagent \((R{-}MgX)\) on hydrolysis with water always gives the corresponding hydrocarbon \((R{-}H)\). Remember: \[ R{-}MgX + H_2O \rightarrow R{-}H \]

Answer 1

The Correct Option is D

Step 1: In situ generation of HBr.
NaBr reacts with concentrated H₂SO₄ to produce HBr, which converts cyclohexanol to cyclohexyl bromide.

Step 2: Grignard reagent preparation.
Cyclohexyl bromide reacts with magnesium in dry ether to form cyclohexyl magnesium bromide.

Step 3: Hydrolysis of the Grignard.
Treatment with water protonates the cyclohexyl group, yielding cyclohexane and Mg(OH)Br.

Step 4: Identifying the final product.
The overall sequence produces cyclohexane.

Step 5: Conclusion.
Hence, the major product is cyclohexane.