How many enols (including stereo isomers) exist for 3 - hexanone?

Options

A. Two
B. Three
C. Four
D. Six

Answer

To determine how many enols (including stereoisomers) exist for 3-hexanone, we will follow these steps:

### Step 1: Identify the structure of 3-hexanone
3-hexanone is a ketone with the following structure:

```
CH3-CH2-C(=O)-CH2-CH3
```

This structure consists of a six-carbon chain (hexane) with a ketone functional group at the third carbon.

### Step 2: Understand enol formation
Enols are formed from ketones through the process of tautomerization, where the carbonyl group (C=O) converts into an alkene (C=C) with an adjacent hydroxyl group (OH).

### Step 3: Identify possible enol structures
For 3-hexanone, the enol can be formed by the following structure:

1. The double bond can be formed between the second and third carbon atoms, leading to the following enol structure:

```
CH3-CH=CHOH-CH2-CH3
```

### Step 4: Determine stereoisomers
The enol can exist in two stereoisomeric forms based on the orientation of the substituents around the double bond:

1. **Cis form**: The hydroxyl group (OH) and the methyl group (CH3) are on the same side.
2. **Trans form**: The hydroxyl group (OH) and the methyl group (CH3) are on opposite sides.

### Step 5: Count the total enols
From the above analysis, we can conclude that:
- There is **one enol structure** that can exist as **two stereoisomers** (cis and trans).

Thus, the total number of enols (including stereoisomers) for 3-hexanone is **2**.

### Final Answer:
The total number of enols (including stereoisomers) for 3-hexanone is **2**.

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