Which among the given compounds will give thermal elimination ?

Options

A. `CH_3-CH_2-Br`
B. `CH_3-CH_2-OH`
C. `{:(" "OCOCH_3),(" "|),(CH_3-CH_2-CH-CH_3):}`
D. All of these

Answer

To determine which compound will undergo thermal elimination, we need to analyze the given compounds based on their leaving groups and the stability of the resulting species after elimination. Here’s a step-by-step solution:

### Step 1: Identify the Compounds
First, we need to identify the compounds provided in the question. Let's assume we have three compounds labeled A, B, and C.

### Step 2: Analyze the Leaving Groups
For thermal elimination to occur, a good leaving group is essential. The leaving group must be able to stabilize itself after it departs. Common good leaving groups include halides (like Br⁻), tosylates, and neutral molecules like water.

- **Compound A**: Has a leaving group OCOCH₃.
- **Compound B**: Has a leaving group OH.
- **Compound C**: Has a leaving group Br.

### Step 3: Evaluate the Stability of Leaving Groups
Next, we evaluate the stability of the leaving groups once they leave:

- **OCOCH₃**: This group can stabilize itself as it forms an acetyl group (CH₃C=O) after leaving, which is stable.
- **OH**: Hydroxide (OH⁻) is not a good leaving group because it is a strong base and does not stabilize well on its own.
- **Br**: Bromide (Br⁻) is a good leaving group, but we need to compare it with OCOCH₃.

### Step 4: Consider the Beta Position
For elimination to occur, we also need to consider the beta hydrogen that can be removed after the leaving group departs. The compound must have a hydrogen atom on the carbon adjacent to the carbon bearing the leaving group.

### Step 5: Determine the Best Candidate for Thermal Elimination
- **Compound A (OCOCH₃)**: Good leaving group and can stabilize after leaving.
- **Compound B (OH)**: Poor leaving group, unlikely to undergo elimination.
- **Compound C (Br)**: Good leaving group, but not as stable as OCOCH₃.

### Conclusion
Based on the analysis, **Compound A** with the leaving group OCOCH₃ is the best candidate for thermal elimination due to the stability of the leaving group after it departs.

### Final Answer
The compound that will give thermal elimination is **Compound A (OCOCH₃)**.

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