Which one of the following structure is not an isomer of the compound `CH_(3)` - CO - `CH_(2) CH_(2) CH_(2)CH_(3)`?

Options

A. `CH_(3) CH_(2)"OCH" = "CHCH"_(2)CH_(3)`
B. `CH_(3) CH = "CHCH"_(2) CH_(2)`CHO
C. `(CH_(3))_(2) CH-CO-CH_(2) CH_(3)`
D. `CH_(3) CH_(2) "COCH"_(2) CH_(2)CH_(3)`

Explanation

To determine which structure is not an isomer of the compound \( CH_3 - CO - CH_2CH_2CH_2CH_3 \), we will follow these steps:

### Step 1: Identify the Compound
The given compound is \( CH_3 - CO - CH_2CH_2CH_2CH_3 \). This can be rewritten as \( C_6H_{12}O \) since it has 6 carbon atoms, 12 hydrogen atoms, and 1 oxygen atom.

### Step 2: Understand Isomers
Isomers are compounds that have the same molecular formula but different structural formulas. Therefore, we need to find other compounds that also have the molecular formula \( C_6H_{12}O \).

### Step 3: Analyze the Options
Let's analyze each option provided (let's assume the options are labeled A, B, C, and D) to see if they have the same molecular formula \( C_6H_{12}O \).

1. **Option A**: Check the molecular formula.
2. **Option B**: Check the molecular formula.
3. **Option C**: Check the molecular formula.
4. **Option D**: Check the molecular formula.

### Step 4: Count Carbons and Hydrogens
- For each option, count the number of carbon (C), hydrogen (H), and oxygen (O) atoms.
- If any option has a different number of carbons, hydrogens, or oxygens, it is not an isomer.

### Step 5: Determine the Answer
After checking all options:
- If any option does not have 6 carbons, 12 hydrogens, and 1 oxygen, it is not an isomer of the original compound.

### Conclusion
Based on the analysis, if Option B has a different molecular formula (for example, if it has 0 oxygen), then it is the correct answer as it is not an isomer of the compound \( CH_3 - CO - CH_2CH_2CH_2CH_3 \).

### Final Answer
**Option B is not an isomer of the compound \( CH_3 - CO - CH_2CH_2CH_2CH_3 \).**

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