But-1-yne can be converted into 1-bromo-1-butene by reacting it with which of the following reagent?

Options

A. HBr
B. HBr and `C_(6)H_(5)COO_(2)`
C. `Br_(2) and H_(2)O_(2)`
D. `Br_(2) and C Cl_(4)`

Explanation

To convert but-1-yne into 1-bromo-1-butene, we need to follow a specific reaction mechanism. Here’s a step-by-step solution:

### Step 1: Identify the Reactants
We start with but-1-yne, which has the structure:
\[ \text{CH}_3\text{CH}_2\text{C} \equiv \text{CH} \]

### Step 2: Choose the Appropriate Reagent
To convert but-1-yne to 1-bromo-1-butene, we need to add HBr in the presence of a peroxide. This is because the presence of peroxide will facilitate an anti-Markovnikov addition.

### Step 3: Understand the Reaction Mechanism
In the presence of HBr and peroxide, the reaction proceeds via a radical mechanism. The triple bond in but-1-yne will break, and the addition of HBr will occur such that:
- The hydrogen atom from HBr will attach to the carbon with fewer hydrogen atoms (the second carbon in this case).
- The bromine atom will attach to the terminal carbon (the first carbon).

### Step 4: Write the Product Structure
After the addition of HBr, the structure will change as follows:
- The triple bond between the first and second carbon will convert into a double bond.
- The product formed will be:
\[ \text{CH}_3\text{CH}_2\text{C}=\text{CHBr} \]
This is 1-bromo-1-butene.

### Step 5: Conclusion
The correct reagent for the conversion of but-1-yne to 1-bromo-1-butene is HBr in the presence of benzoyl peroxide.

### Final Answer
The correct answer is **HBr and benzoyl peroxide** (Option 2).

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