What product would you expect to obtain from Grignard reaction when an excess of phenylmagnesium bromide reacts with dimethyl carbonate `CH_(3)OCOOCH_(3)` ?

Options

A. `CH_(3)-underset(Ph)underset(|)overset(OH)overset(|)(C)-Ph`
B. `CH_(3)-overset(OH)overset(|)(CH)-Ph`
C. `Ph-underset(Ph)underset(|)overset(OH)overset(|)(C)-Ph`
D. `CH_(3)-overset(O)overset(||)(C)-Ph`

Explanation

To determine the product obtained from the Grignard reaction when an excess of phenylmagnesium bromide reacts with dimethyl carbonate, we can follow these steps:

### Step 1: Understand the Reactants
Dimethyl carbonate (CH₃OCOOCH₃) is an ester, and phenylmagnesium bromide (PhMgBr) is a Grignard reagent. Grignard reagents are nucleophiles that can react with electrophiles such as carbonyl compounds.

### Step 2: Identify the Electrophilic Site
In dimethyl carbonate, the carbonyl carbon (C=O) is electrophilic and will react with the nucleophilic phenyl group from the Grignard reagent.

### Step 3: First Nucleophilic Attack
When phenylmagnesium bromide reacts with dimethyl carbonate, the phenyl group (Ph) attacks the electrophilic carbon of the carbonyl group. This leads to the formation of a tetrahedral intermediate. The reaction can be represented as follows:

\[ \text{PhMgBr} + \text{CH}_3OCOOCH_3 \rightarrow \text{PhC(OH)(OCH}_3)(OCH_3)^{-} \]

### Step 4: Collapse of the Tetrahedral Intermediate
The tetrahedral intermediate will collapse, leading to the elimination of one of the methoxy groups (OCH₃) as a methoxide ion (OCH₃⁻). This results in the formation of a new carbonyl compound:

\[ \text{PhC(=O)(OCH}_3) + \text{OCH}_3^{-} \]

### Step 5: Second Nucleophilic Attack
Since we have an excess of phenylmagnesium bromide, another phenyl group can attack the newly formed carbonyl carbon. This leads to another nucleophilic addition:

\[ \text{PhC(=O)(OCH}_3) + \text{PhMgBr} \rightarrow \text{PhC(OH)(Ph)(OCH}_3)^{-} \]

### Step 6: Final Product Formation
The final product after hydrolysis (adding water) will yield a tertiary alcohol:

\[ \text{PhC(OH)(Ph)(OCH}_3) + \text{MgBr}^+ \]

### Final Product
The final product is a tertiary alcohol, specifically diphenylmethanol with a methoxy group:

\[ \text{(Ph)₂C(OH)(OCH}_3) \]

### Conclusion
The expected product from the reaction of excess phenylmagnesium bromide with dimethyl carbonate is a tertiary alcohol, specifically diphenylmethanol with a methoxy group.