IUPAC name of `CH_(3)CH_(2)CH_(2)CH(CH_(3))COCH_(3)` is

Options

A. isohexanone
B. heptanone
C. hexanone-5
D. 3-Methylhexan-2-one.

Answer

To determine the IUPAC name of the compound `CH₃CH₂CH₂CH(CH₃)COCH₃`, we will follow these steps:

### Step 1: Identify the Structure
The given molecular formula can be broken down into its structural components:
- The compound consists of a chain of carbon atoms with a ketone functional group (C=O).
- The structure can be visualized as:

```
CH3
|
CH3-CH2-CH2-CH-CO-CH3
```

### Step 2: Count the Carbon Atoms
Count the total number of carbon atoms in the longest continuous chain:
- The longest chain has 6 carbon atoms (from the leftmost CH₃ to the rightmost CH₃).

### Step 3: Identify the Functional Group
The main functional group in this compound is a ketone (C=O). In this case, the ketone is located at the 4th carbon when counting from the end closest to the functional group.

### Step 4: Number the Carbon Chain
Number the carbon chain starting from the end nearest to the ketone group:
- The numbering will be:
1. CH₃ (1)
2. CH₂ (2)
3. CH₂ (3)
4. CH (4) - this carbon is attached to the ketone
5. C=O (5)
6. CH₃ (6)

### Step 5: Identify Substituents
There is a methyl (CH₃) group attached to the 4th carbon:
- This substituent is located at position 4.

### Step 6: Construct the Name
Combine the information:
- The base name for a 6-carbon chain with a ketone is "hexanone".
- Since the ketone is at the 4th carbon, it becomes "4-hexanone".
- Additionally, there is a methyl group at the 4th carbon, so we denote it as "4-methyl".

### Final IUPAC Name
Putting it all together, the IUPAC name of the compound is **4-methyl-2-hexanone**.