Question

An organic compound [X] (Molecular formula \( C_6H_{12}O_2 \)) reacts with dil. \( H_2SO_4 \) to form an alcohol [B] and a carboxylic acid [C]. Reaction of compound [B] with Jones reagent yielded compound [C]. When compound [C] was heated with \( P_2O_5 \) an Anhydride was formed. Compound [X] is --------

• A. \( C_2H_5 - COO - (CH_2)_2 - CH_3 \)
• B. \( CH_3 - COO - (CH_2)_3 - CH_3 \)
• C. \( CH_3 - COO - CH_2 - CH - (CH_3)_2 \)
• D. \( CH_3 - COO - C - (CH_3)_3 \)

Hint:

Ester hydrolysis gives alcohol + acidIf alcohol oxidizes to acid, it must be a primary alcohol.

Answer 1

The Correct Option is A

Step 1: Identify functional group of [X].
Compound gives alcohol and acid on hydrolysis with dil. \( H_2SO_4 \).
So, \( [X] \) must be an ester.

Step 2: General reaction of ester hydrolysis.
\[ R-COO-R' \xrightarrow{H^+} R-COOH + R'-OH \]
So:
\[ [B] = \text{alcohol}, \quad [C] = \text{carboxylic acid} \]

Step 3: Use Jones reagent condition.
Jones reagent oxidizes primary alcohol to carboxylic acid.
Since \( [B] \rightarrow [C] \), alcohol must be primary alcohol.

Step 4: Use anhydride formation.
Heating \( [C] \) with \( P_2O_5 \) forms anhydride.
This confirms \( [C] \) is a carboxylic acid.

Step 5: Match molecular formula.
Given formula: \( C_6H_{12}O_2 \) corresponds to ester.

Step 6: Check correct structure.
Option (A):
\[ C_2H_5COO(CH_2)_2CH_3 \]
On hydrolysis:
\[ C_2H_5COOH + CH_3CH_2CH_2OH \]
Alcohol is primary → can oxidize to acid.

Step 7: Final conclusion.
\[ \boxed{C_2H_5 - COO - (CH_2)_2 - CH_3} \]