An ester (X) with molecular formula `C_9 H_(10) O_2` was treated with excess of `CH_3 Mg Br` and the complex so formed, was treated with `H_2 SO_4` to give an alkene (Y) whose ozonolysis gave a ketone with molecular formula `C_8 H_8 O` which shows positive iodoform test. The structure of (X) is

Options

A. `C_6H_5COOC_2H_5`
B. `C_6H_5COOC_6H_5`
C. `H_3C COO C_6H_5`
D. `p-H_3COC_6H_4COCH_3`

Explanation

To determine the structure of the ester (X) with the molecular formula C9H10O2, we can follow these steps:

### Step 1: Identify the Ester
The molecular formula of the ester is C9H10O2. Esters are derived from carboxylic acids and alcohols. The general formula for an ester is RCOOR', where R and R' are hydrocarbon chains.

### Step 2: Analyze the Reaction with Grignard Reagent
When the ester is treated with excess CH3MgBr (a Grignard reagent), it forms a tertiary alcohol after hydrolysis. This indicates that the ester must have a structure that allows for the formation of a tertiary alcohol upon reaction with the Grignard reagent.

### Step 3: Consider Possible Structures
We need to consider the options given:
- Option A: C6H5COOC2H5 (Ethyl benzoate)
- Option B: C6H5COOC6H5 (Benzyl benzoate)
- Option C: CH3COOC6H5 (Acetophenone)
- Option D: Paramethoxyacetophenol

### Step 4: Evaluate Each Option
1. **Option A (Ethyl benzoate)**:
- Upon reaction with CH3MgBr, it would form a tertiary alcohol, which can then dehydrate to form an alkene.
- The ozonolysis of the alkene would yield a ketone that can give a positive iodoform test.

2. **Option B (Benzyl benzoate)**:
- This would not lead to a tertiary alcohol upon reaction with CH3MgBr, as it would not have the necessary structure.

3. **Option C (Acetophenone)**:
- This is not an ester and thus cannot be the starting material.

4. **Option D (Paramethoxyacetophenol)**:
- This structure does not fit the criteria for forming a tertiary alcohol from the reaction with CH3MgBr.

### Step 5: Confirm the Correct Structure
From the analysis, **Option A (Ethyl benzoate)** is the only structure that fits all the criteria:
- It reacts with CH3MgBr to form a tertiary alcohol.
- The tertiary alcohol can dehydrate to form an alkene.
- The ozonolysis of the alkene yields a ketone that shows a positive iodoform test.

### Conclusion
The structure of the ester (X) is **C6H5COOC2H5 (Ethyl benzoate)**.

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