The correct IUPAC name of 2-chloro-3-butanol is :-

Options

A. 3-Chloro-2-hydroxy butane
B. 3-Chloro-2-butanol
C. 3-Hydroxy -2-chloro butane
D. 2-Chloro-3-hydroxy butane

Answer

To determine the correct IUPAC name of 2-chloro-3-butanol, we will follow a systematic approach. Here’s a step-by-step solution:

### Step 1: Understand the given name
The name "2-chloro-3-butanol" indicates that we have a butanol compound (which means it has a four-carbon chain) with a chlorine substituent on the second carbon and an alcohol (-OH) group on the third carbon.

### Step 2: Draw the structure
1. Start by drawing a four-carbon chain (butane):
- C1 - C2 - C3 - C4
2. Place the -OH group (alcohol) on the third carbon (C3).
3. Place the chlorine (Cl) on the second carbon (C2).

The structure will look like this:
```
CH3
|
CH3-CH-CH-CH3
| |
Cl OH
```

### Step 3: Number the carbon chain
Number the carbon atoms from the end closest to the functional group (the -OH group) to give it the lowest possible number:
1. C1: CH3
2. C2: CH (with Cl)
3. C3: CH (with OH)
4. C4: CH3

### Step 4: Identify substituents and functional groups
- The substituent is chlorine (Cl) on C2.
- The functional group is the hydroxyl (-OH) on C3.

### Step 5: Write the IUPAC name
1. Start with the substituent: "2-chloro" (since Cl is on C2).
2. Next, identify the parent name: "butanol" (since the longest chain has four carbons and contains an alcohol).
3. The position of the alcohol group is C3, so we modify "butanol" to "butan-3-ol".

### Step 6: Combine the parts
The complete IUPAC name is:
**3-chloro-2-butanol**

### Final Answer
The correct IUPAC name of 2-chloro-3-butanol is **3-chloro-2-butanol**.

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