Question

What would be the major product of the given reaction? \[ HCHO + CH_3MgI \xrightarrow{H_2O} \; ? \]

• A. Ethanal
• B. Propanol
• C. Ethanol
• D. Propanal

Hint:

Formaldehyde always gives primary alcohols on reaction with Grignard reagents.

Answer 1

The Correct Option is C

Step 1: The given reaction involves formaldehyde (\( HCHO \)) reacting with methyl magnesium iodide (\( CH_3MgI \)), a Grignard reagent.
Step 2: Grignard reagents add to the carbonyl carbon of aldehydes and ketones to form alcohols after hydrolysis.
Formaldehyde specifically gives a primary alcohol.
Step 3: The methyl group (\( CH_3 \)) from the Grignard reagent adds to the carbon of formaldehyde:
\[ HCHO + CH_3MgI \longrightarrow CH_3{-}CH_2O^{-}MgI^{+} \xrightarrow{H_2O} CH_3CH_2OH \] Step 4: The product is ethanol (\( CH_3CH_2OH \)), which is a primary alcohol.