Which of the following Grignard Reagent will be used to prepare the given alcohol when treated with methanal ?
Show Hint
- \(CH_3MgBr\)
- [structure (B) - image pending]
- [structure (C) - image pending]
- [structure (D) - image pending]
The Correct Option is A
Solution and Explanation
A Grignard reagent (\(R-MgBr\)) adds to methanal (formaldehyde, HCHO). After hydrolysis it gives a primary alcohol \(R-CH_2OH\), where the new alcohol has one more carbon than the alkyl group of the Grignard reagent.
Step 1:
The target alcohol's structure determines the required R group: take the target primary alcohol, remove the \(-CH_2OH\) carbon, and the remaining group is R in \(R-MgBr\).
Step 2:
If the target alcohol is ethanol (\(CH_3CH_2OH\)), the required Grignard reagent is \(CH_3MgBr\), since \(CH_3MgBr + HCHO \rightarrow CH_3CH_2OH\) after hydrolysis.
Answer: Option (A) \(CH_3MgBr\) (assuming the target alcohol shown is ethanol; confirm from the printed structure image).
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