`PhMgBr+underset((2)H^(o+))overset((1)X)rarrPh-underset(Ph)underset(|)overset(OH)overset(|)C-Ph`
X is

Options

A. `Ph-overset(O)overset(||)C-H`
B. `Ph-overset(O)overset(||)C-Ph`
C. `Ph-underset(Ph)underset(|)(CH)-overset(O)overset(||)C-H`
D. `Ph-overset(O)overset(||)C-CH_3`

Answer

To solve the question, we need to identify the compound X that reacts with PhMgBr and produces the specified product after the addition of H⁺. Let's break down the steps:

### Step 1: Understanding the Reactants
- We have PhMgBr, which is a Grignard reagent. Grignard reagents are strong nucleophiles and will react with electrophiles.
- The question indicates that we will react PhMgBr with a compound X, followed by the addition of H⁺.

### Step 2: Analyzing the Product
- The product is given as Ph-Ph-CH(OH)-Ph, which indicates that we have a tertiary alcohol with three phenyl (Ph) groups attached to a carbon that also has a hydroxyl (OH) group.

### Step 3: Identifying Possible Candidates for X
- We need to determine which of the four options can serve as X to produce the desired product.
- The compound X must have a carbonyl (C=O) group since Grignard reagents typically react with carbonyl compounds to form alcohols.

### Step 4: Testing Each Option
1. **Option 1**: If we assume X is PhCHO (benzaldehyde), the reaction would yield:
- PhMgBr attacks the carbonyl carbon, leading to the formation of a compound with a negative charge on oxygen.
- After protonation, we would get Ph-CH(OH)-Ph, which is not the desired product.

2. **Option 2**: If X is PhCOPh (benzophenone), the reaction would yield:
- PhMgBr attacks the carbonyl carbon of PhCOPh, forming a compound with a negative charge on oxygen.
- After protonation, we would get Ph-CH(OH)-Ph, which matches the desired product.

3. **Option 3**: If X is PhC(OH)Ph, the reaction would not yield the desired product as it already contains an alcohol group.

4. **Option 4**: If X is PhC(O)CH₃ (acetophenone), the reaction would yield:
- PhMgBr attacks the carbonyl carbon, leading to a compound that does not match the desired product.

### Step 5: Conclusion
- Based on the analysis, **Option 2 (PhCOPh)** is the correct choice for X, as it leads to the formation of the desired product after the reaction with PhMgBr and subsequent protonation.

### Final Answer
**X is PhCOPh (benzophenone).**

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