The `IUPAC` name of `CH_(3)COCH(CH_(3))_(2)` is

Options

A. isopropyl methyl ketone
B. 2-methyl-3-butanone
C. 4-methylisopropyl ketone
D. 3-methyl-2-butanone

Answer

To determine the IUPAC name of the compound \( CH_3COCH(CH_3)_2 \), we will follow these steps:

### Step 1: Identify the Structure
First, we need to draw the structure of the compound based on its molecular formula. The compound consists of:
- A carbonyl group (C=O) indicating that it is a ketone.
- Two methyl groups attached to the second carbon.

### Step 2: Number the Carbon Chain
Next, we will number the carbon chain. In IUPAC nomenclature, we should number the chain in such a way that the functional group (the carbonyl group in this case) gets the lowest possible number.

1. Start numbering from the end closest to the carbonyl group:
- Carbon 1: \( CH_3 \) (methyl group)
- Carbon 2: \( CO \) (carbonyl group)
- Carbon 3: \( CH \) (with two methyl groups attached)
- Carbon 4: \( CH_3 \) (methyl group)

### Step 3: Identify the Parent Chain
The longest continuous carbon chain that includes the carbonyl group is four carbons long, which corresponds to butane. Since the carbonyl group is on the second carbon, the base name of the compound is "butanone".

### Step 4: Identify and Name the Substituents
Now, we need to identify the substituents:
- There is a methyl group (–CH₃) attached to the third carbon.

### Step 5: Combine the Information
Now, we combine the information:
- The parent chain is butanone (due to the ketone functional group).
- The methyl substituent is located at the third carbon.

Thus, we write the full IUPAC name as "3-methyl-2-butanone".

### Final Answer
The IUPAC name of \( CH_3COCH(CH_3)_2 \) is **3-methyl-2-butanone**.

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