Which of the following compound will not react with `l_(2)//OH^(-)`.

Options

A.
B.
C.
D. `CH_3-CHO`

Answer

To determine which of the given compounds will not react with iodine (I2) in the presence of hydroxide ions (OH-), we need to identify if any of the compounds contain a methyl ketone group (CH3CO-). The presence of this group is essential for a positive iodoform test.

### Step-by-step Solution:

1. **Understand the Iodoform Reaction**: The iodoform reaction occurs when a compound contains a methyl ketone (CH3CO-) or a secondary alcohol that can be oxidized to a methyl ketone. Compounds without these functional groups will not react.

2. **Analyze Each Compound**:
- **Option A**: This compound has a phenyl ring attached to a carbonyl group (C=O) and a methyl group (CH3). The structure can be represented as Ph-CO-CH3, which indicates that it contains a methyl ketone. Therefore, it will give a positive iodoform test.
- **Option B**: Similar to Option A, this compound also contains a methyl ketone group (CH3CO-). Thus, it will also give a positive iodoform test.
- **Option C**: This compound has a structure that includes a phenyl ring, a CH2 group, and a carbonyl group (C=O). The structure can be represented as Ph-CH2-CO-H. Since there is no methyl group (CH3) adjacent to the carbonyl, this compound does not contain a methyl ketone group and will not give a positive iodoform test.
- **Option D**: This compound contains a methyl group adjacent to a carbonyl group (CH3CO-H). Therefore, it contains a methyl ketone and will give a positive iodoform test.

3. **Conclusion**: Based on the analysis, the compound that will not react with I2 and OH- is **Option C**.

### Final Answer:
The compound that will not react with I2/OH- is **Option C**.