The IUPAC name of `underset(COOH)underset(|) CH_2 - CH_2 - underset(COOH) underset(|) CH_2 ` is

Options

A. Pentane-1, 5-dioic acid
B. Pentane-1, 5-dicarboxylic acid
C. Propane-1,3-dioic acid
D. none of these

Explanation

To determine the IUPAC name of the compound with the structure `HOOC-CH2-CH2-COOH`, we can follow these steps:

### Step 1: Identify the Parent Carbon Chain
- The first step is to identify the longest continuous carbon chain that includes the functional groups. In this case, we have a total of 5 carbon atoms in the chain.

### Step 2: Number the Carbon Atoms
- Next, we need to number the carbon atoms in the parent chain. We can start numbering from either end of the chain.
- If we number from the left (HOOC-CH2-CH2-COOH), we get:
- 1: COOH (carboxylic acid)
- 2: CH2
- 3: CH2
- 4: CH2
- 5: COOH (carboxylic acid)
- Alternatively, if we number from the right, we get the same positions for the functional groups:
- 1: COOH
- 2: CH2
- 3: CH2
- 4: CH2
- 5: COOH

### Step 3: Determine the Name Based on the Numbering
- Since there are 5 carbon atoms in the longest chain, the base name will be derived from "pentane".
- We have two carboxylic acid groups (COOH) located at positions 1 and 5. Therefore, we use the prefix "di-" to indicate that there are two carboxylic acid groups.
- The suffix for carboxylic acids is "oic acid".

### Step 4: Combine the Elements for the Final Name
- Combining all the information, we have:
- Parent chain: pentane
- Number of carboxylic acid groups: di
- Functional group suffix: oic acid
- Therefore, the IUPAC name of the compound is **pentane-1,5-dioic acid**.

### Final Answer
The IUPAC name of the compound is **pentane-1,5-dioic acid**.

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