The IUPAC name of given compound is
`CH_3-underset(CH_2CH_3)underset(|)(CH)-CHO`

Options

A. Butan -2- aldehyde
B. 2- methylbutanal
C. 3 - methyl isobutyraldehyde
D. 2 - ethylpropanal

Answer

To determine the IUPAC name of the given compound, we will follow these steps:

### Step 1: Identify the longest carbon chain
The compound is represented as `CH3-CH(CH2CH3)-CHO`. We need to identify the longest continuous carbon chain in the structure.

- The longest chain here consists of 4 carbon atoms:
- CH3 (1)
- CH (2)
- CH2 (3)
- CHO (4)

### Step 2: Number the carbon chain
Number the carbon chain starting from the end nearest to the functional group (the aldehyde group -CHO).

- So, we number the chain as follows:
- C1: CHO (aldehyde)
- C2: CH
- C3: CH2
- C4: CH3

### Step 3: Identify and name substituents
In this case, we have a methyl group (CH3) attached to the second carbon of the main chain.

- The substituent is a methyl group located at carbon 2.

### Step 4: Combine the names
Now we combine the names of the substituents and the main chain.

- The longest carbon chain is butane (4 carbons).
- The substituent is a methyl group at position 2.

Thus, the name of the compound is **2-methylbutanal**.

### Step 5: Finalize the IUPAC name
Since the aldehyde functional group takes priority in naming, we do not need to indicate the position of the aldehyde group (which is always at carbon 1).

The final IUPAC name of the compound is **2-methylbutanal**.

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