Which one is not an allylic halide?

Options

A. 3 - chloro cyclo hex -1 - ene
B. 1 - chloro but -2- ene
C. 1 - chloro prop -1- ene.
D. 3 - chloro prop -1- ene

Answer

To determine which compound is not an allylic halide, we first need to understand the definitions of allylic and vinylic halides.

### Step 1: Define Allylic Halide
An allylic halide is an organic compound where a halogen atom is attached to a carbon atom that is adjacent to a carbon-carbon double bond (the allylic carbon).

### Step 2: Define Vinylic Halide
A vinylic halide is an organic compound where a halogen atom is directly attached to a carbon atom that is part of a carbon-carbon double bond.

### Step 3: Analyze Each Option
We will analyze each of the given options to see if they are allylic halides or not.

1. **3-Chlorocyclohex-1-ene**:
- Structure: The chlorine is attached to a carbon adjacent to the double bond in the cyclohexene structure.
- Conclusion: This is an allylic halide.

2. **1-Chlorobutene**:
- Structure: The chlorine is attached to the carbon adjacent to the double bond.
- Conclusion: This is also an allylic halide.

3. **1-Chloroprop-1-ene**:
- Structure: The chlorine is directly attached to the carbon that is part of the double bond.
- Conclusion: This is a vinylic halide, not an allylic halide.

4. **3-Chloroprop-1-ene**:
- Structure: The chlorine is attached to a carbon adjacent to the double bond.
- Conclusion: This is an allylic halide.

### Step 4: Identify the Answer
From the analysis, the compound that is **not an allylic halide** is **1-Chloroprop-1-ene**, as it is a vinylic halide.

### Final Answer
The compound that is not an allylic halide is **1-Chloroprop-1-ene**.

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