Which the following does not respond to iodoform reaction ?

Options

A. `(CH_3)_2CHCH(OH)CH_3`
B. `PhCH_2CHOHCH_3`
C. `phCH(OH)CH_2CH_3`
D. `CH_3CH_2OH`

Answer

To determine which of the following compounds does not respond to the iodoform reaction, we need to understand the conditions under which the iodoform test is positive. The iodoform reaction is a test for the presence of methyl ketones or secondary alcohols that can be oxidized to methyl ketones.

### Steps to Solve the Problem:

1. **Understand the Iodoform Reaction**:
- The iodoform reaction is a test that indicates the presence of a methyl group (CH3) adjacent to a carbonyl group (C=O) in ketones or alcohols.
- The reaction typically involves the use of iodine and sodium hydroxide (NaOH) and produces a yellow precipitate of iodoform (CHI3).

2. **Identify the Structure of Each Compound**:
- We need to analyze each option to see if they contain the required structure for a positive iodoform test.

3. **Analyze Each Option**:
- **Option A**: CH3-CH(OH)-CH3 (This is a secondary alcohol with a methyl group adjacent to the hydroxyl group, so it will give a positive iodoform test.)
- **Option B**: C6H5-CH2-CHOH-CH3 (This compound has a hydroxyl group, but it does not have a methyl group adjacent to the carbonyl, so it will not give a positive iodoform test.)
- **Option C**: C6H5-CH(OH)-CH2-CH3 (This compound has a hydroxyl group with a methyl group adjacent to it, so it will give a positive iodoform test.)
- **Option D**: CH3-CH2-OH (This is a primary alcohol and does not have a methyl group adjacent to a carbonyl, so it will not give a positive iodoform test.)

4. **Conclusion**:
- After analyzing all options, we find that **Option B** (C6H5-CH2-CHOH-CH3) does not respond to the iodoform reaction.

### Final Answer:
The compound that does not respond to the iodoform reaction is **Option B**.