In the following reaction sequence Y is,
`PhOCOCH_(3) underset(Delta)overset(AlCl_(3))rarr (X) underset(NaOH)overset(I_(2))rarr (Y)`

Options

A. PhCOONa
B. PhCOOH
C.
D.

Explanation

To solve the problem step by step, we will analyze the reaction sequence provided and deduce the structure of compound Y.

### Step 1: Identify the starting compound
The starting compound is `PhOCOCH3`, which is a phenyl group (Ph) attached to a carbonyl (C=O) and a methyl group (CH3).

### Step 2: Reaction with AlCl3 and heat
When `PhOCOCH3` is treated with AlCl3 and heat, it undergoes a Friedel-Crafts acylation reaction. The lone pair of electrons on the oxygen atom of the carbonyl group coordinates with AlCl3, forming a complex. This activates the carbonyl carbon for electrophilic attack.

**Intermediate structure:**
- The structure can be represented as:
```
PhO-C(=O)-CH3
```
After coordination with AlCl3, the carbonyl carbon becomes more electrophilic.

### Step 3: Formation of the acyloxybenzene
The acyloxybenzene is formed after the loss of CH3C≡O (acetyl group) as a leaving group. The resulting structure after the rearrangement will be:
```
Ph-O-C(=O)-CH3
```
This structure has a negative charge on the oxygen after the rearrangement.

### Step 4: Reaction with I2 and NaOH
The next step involves treating the product with I2 and NaOH. This is indicative of the iodoform reaction, which occurs with methyl ketones or compounds that can generate a methyl ketone.

1. The negative charge on the oxygen can facilitate the formation of a hydroxyl group.
2. The iodoform reaction will convert the methyl group adjacent to the carbonyl into iodoform (CHI3) and leave behind a carboxylate ion.

**Final product structure:**
The final product Y will be:
```
Ph-O-C(=O)-Na
```
Where the sodium ion is associated with the carboxylate group.

### Conclusion
Thus, the final product Y is `PhOCOONa` (sodium phenyl carbonate).