Identify the product ' B ' in following reaction. \(\text{Dry ice} \xrightarrow[\text{dry ether}]{\text{CH}_3\text{MgBr}} \text{A} \xrightarrow{\text{H}_3\text{O}^+} \text{B}\)
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Grignard reagent + \(\text{CO}_2\) + hydrolysis gives a carboxylic acid with one extra carbon atom.
Step 1: Understanding the Concept:
Reaction of a Grignard reagent (\(\text{R-MgX}\)) with solid carbon dioxide (\(\text{Dry ice}\)) followed by acid hydrolysis produces a carboxylic acid with one more carbon than the Grignard reagent. Step 2: Key Formula or Approach:
\[ \text{CO}_2 + \text{R-MgX} \rightarrow \text{R-COOMgX} \xrightarrow{\text{H}_3\text{O}^+} \text{R-COOH} \]
Step 3: Detailed Explanation:
1. Addition: Methyl magnesium bromide (\(\text{CH}_3\text{MgBr}\)) adds to \(\text{CO}_2\):
\[ \text{O=C=O} + \text{CH}_3\text{MgBr} \xrightarrow{\text{dry ether}} \text{CH}_3\text{-CO-OMgBr (Product A)} \]
2. Hydrolysis: The addition complex 'A' is hydrolyzed:
\[ \text{CH}_3\text{-CO-OMgBr} \xrightarrow{\text{H}_3\text{O}^+} \text{CH}_3\text{COOH (Product B)} + \text{Mg(OH)Br} \]
The final product 'B' is Ethanoic acid (Acetic acid). Step 4: Final Answer:
Product 'B' is Ethanoic acid.