The `IUPAC` name of `HOCH_(2)CH=C(CH_(3))_(2)` is:

Options

A. `2`-Methyl-`2`-buten `4`-ol
B. `3`-Methyl-`2`-buten `1`-ol
C. `2`-Methyl-`2`-butanol
D. `3`-Methyl-`2`-butenol

Answer

To find the IUPAC name of the compound \( HOCH_2CH=C(CH_3)_2 \), we will follow these steps:

### Step 1: Draw the Structure
The compound can be represented as follows:
- Start with the carbon backbone: \( CH_2 \) (first carbon), \( CH \) (second carbon), \( C \) (third carbon with a double bond), and \( CH_3 \) (methyl groups on the third carbon).
- The hydroxyl group (OH) is attached to the first carbon.

The structure can be drawn as:
```
CH3
|
CH3-C=CH-CH2-OH
```

### Step 2: Number the Carbon Chain
We need to number the carbon chain, giving priority to the functional group (OH) over the double bond. The numbering starts from the end closest to the OH group:
1. Carbon 1: \( OH \) (hydroxyl group)
2. Carbon 2: \( CH \) (double bond here)
3. Carbon 3: \( C \) (with two methyl groups)
4. Carbon 4: \( CH_2 \)

### Step 3: Identify Substituents
The substituent on the third carbon is a methyl group. Since there are two methyl groups on the third carbon, we denote this as "3-methyl".

### Step 4: Determine the Main Chain and Functional Groups
- The main carbon chain consists of 4 carbons (butane).
- There is a double bond between carbon 2 and carbon 3, which is indicated as "2-en".
- The hydroxyl group is on carbon 1, indicated as "1-ol".

### Step 5: Combine the Information
Now we can combine all the information to write the IUPAC name:
- Start with the substituent: "3-methyl"
- Follow with the main chain: "but"
- Indicate the double bond: "2-en"
- Indicate the alcohol: "1-ol"

Thus, the complete IUPAC name is:
**3-methylbut-2-en-1-ol**

### Final Answer
The IUPAC name of \( HOCH_2CH=C(CH_3)_2 \) is **3-methylbut-2-en-1-ol**.

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