Which one will give positive iodoform test?

Options

A. `CH_(3) - CH_(2) `- OH
B. `CH_(3) - "COOCH"_(3)`
C. `CH_(3) - CH_(2) - CO - CH_(3) - CH_(3)`
D. `CH_(3) - underset(CH_(3))underset(|)(CH) - CO - CH_(2) - CH_(3)`

Answer

To determine which compound will give a positive iodoform test, we need to understand the conditions required for this test. The iodoform test is positive for compounds that contain a methyl ketone group (CH3C=O) or for certain alcohols that can be oxidized to form such a group.

### Step-by-Step Solution:

1. **Identify the Compounds**: We need to analyze the given compounds to see if they can yield a methyl ketone or can be oxidized to form one.

2. **Understanding the Iodoform Test**:
- The iodoform test is positive for compounds that have a methyl group adjacent to a carbonyl group (C=O).
- This includes methyl ketones (like acetone) and certain secondary alcohols that can be oxidized to methyl ketones.

3. **Analyzing Each Compound**:
- **Compound 1**: CH3CH2OH (Ethanol)
- Ethanol can be oxidized to acetaldehyde (CH3CHO), which has the methyl ketone structure. Thus, it will give a positive iodoform test.

- **Compound 2**: CH3C(=O)OCH3 (Methyl Acetate)
- This compound does not have a free methyl ketone structure because the carbonyl carbon is bonded to an oxygen atom, preventing it from being oxidized to a methyl ketone. Therefore, it will not give a positive iodoform test.

- **Compound 3**: CH3CH2C(=O)CH2CH3 (Butan-2-one)
- This compound is a ketone but does not have a methyl group adjacent to the carbonyl carbon. Thus, it will not give a positive iodoform test.

- **Compound 4**: CH3C(CH3)C(=O)OCH2 (2-Butanol)
- This compound does not have a methyl group adjacent to the carbonyl carbon either, so it will not give a positive iodoform test.

4. **Conclusion**: Based on the analysis, only **Compound 1 (Ethanol)** will give a positive iodoform test.

### Final Answer:
The compound that will give a positive iodoform test is **Compound 1 (Ethanol)**.