Which of the following is propargyl group?

Options

A. (a) `-CH_2-C-=CH`
B. (b) `-C-=C-Me`
C. (c) `-C-=CH`
D. (d) `-C-=C-CH_2-CH_3`

Explanation

To determine which of the given options represents the propargyl group, we need to understand the structure of the propargyl group itself.

### Step-by-Step Solution:

1. **Definition of Propargyl Group**:
The propargyl group is an alkyl functional group derived from propyne (or 2-propyne) and is represented as -C≡C-CH2-. This means it has a carbon-carbon triple bond followed by a carbon with two hydrogen atoms.

2. **Structure Representation**:
The propargyl group can be represented structurally as:
\[ H - C \equiv C - CH_2 - \]
Here, the first carbon is part of the triple bond, the second carbon is also part of the triple bond, and the third carbon (CH2) is a part of the alkyl chain.

3. **Analyzing the Options**:
Now, let's analyze the options provided to identify which one corresponds to the propargyl group:
- **Option A**: \( CH_2 \equiv C - CH \)
- This matches the structure of the propargyl group.
- **Option B**: \( C \equiv C - CH_2 \)
- This represents an ethynyl group, not propargyl.
- **Option C**: \( C \equiv C - CH_3 \)
- This is also incorrect as it does not have the correct structure.
- **Option D**: Ethyl group (C2H5)
- This is a simple alkyl group and does not represent a propargyl group.

4. **Conclusion**:
Based on the analysis, the correct answer is **Option A**: \( CH_2 \equiv C - CH \).