The major product of the following reaction :
`(CH_(3)O)_(2)COunderset("hydrolysis")overset(C_(2)H_(5)MgBr//"excess")rarr`is :

Options

A. `(C_(2)H_(5))_(3)COH`
B. `(CH_(3))_(3)COH`
C. `C_(2)H_(5)COC_(2)H_(5)`
D. `HCOOH`.

Explanation

To solve the problem, we need to analyze the reaction involving the compound (CH₃O)₂CO and the reagent C₂H₅MgBr under hydrolysis conditions. Let's break down the steps involved in determining the major product of this reaction.

### Step-by-Step Solution:

1. **Identify the Reactants**:
The reactants are (CH₃O)₂CO (dimethyl carbonate) and C₂H₅MgBr (ethyl magnesium bromide), which is a Grignard reagent.

2. **Understand the Reaction**:
Grignard reagents react with carbonyl compounds (like ketones and aldehydes) to form alcohols. In this case, (CH₃O)₂CO has a carbonyl group (C=O) that can react with the Grignard reagent.

3. **Nucleophilic Attack**:
The ethyl group (C₂H₅) from the Grignard reagent acts as a nucleophile and attacks the carbonyl carbon of (CH₃O)₂CO. This leads to the formation of a tetrahedral intermediate.

4. **Formation of the Intermediate**:
The tetrahedral intermediate will have the structure:
\[ (CH₃O)C(OH)(C₂H₅)(OCH₃) \]
Here, one of the methoxy groups (OCH₃) is still attached to the carbon.

5. **Collapse of the Intermediate**:
The tetrahedral intermediate will collapse, leading to the elimination of one of the methoxy groups. This gives us a ketone:
\[ C₂H₅C(=O)(OCH₃) \]

6. **Second Nucleophilic Attack**:
The same Grignard reagent (C₂H₅MgBr) can attack the newly formed ketone. The ethyl group again attacks the carbonyl carbon, forming another tetrahedral intermediate.

7. **Final Product Formation**:
Upon hydrolysis (addition of water and acid), the final product will be:
\[ C₂H₅C(OH)(C₂H₅)(O) \]
This can be simplified to:
\[ C₂H₅C(OH)(C₂H₅)O \]
or written as:
\[ C₂H₅C(OH)(C₂H₅)O \]

8. **Conclusion**:
The major product of the reaction is:
\[ C₂H₅C(OH)(C₂H₅)O \]
This is a tertiary alcohol with two ethyl groups attached to the carbon bearing the hydroxyl group.

### Final Answer:
The major product of the reaction is:
\[ C₂H₅C(OH)(C₂H₅)O \]

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