The `IUPAC` name of viny1 acetylene is:

Options

A. Pent-1-en-4-yne
B. Pent-4-yn-1-ene
C. But-1-en-3-yne
D. But-1-yn-3-ene

Explanation

To determine the IUPAC name of vinyl acetylene, we can follow these steps:

### Step 1: Identify the Structure
Vinyl acetylene consists of a vinyl group (CH2=CH-) and an acetylene group (C≡C). The overall structure can be represented as CH2=CH-C≡C-H.

### Step 2: Determine the Longest Carbon Chain
The longest continuous carbon chain that includes both the double bond and the triple bond is four carbons long. This chain can be numbered starting from the end closest to the double bond, as double bonds take precedence over triple bonds in nomenclature.

### Step 3: Number the Carbons
Number the carbon atoms in the longest chain:
1. The first carbon (C1) has a double bond.
2. The second carbon (C2) is connected to the first.
3. The third carbon (C3) has a triple bond.
4. The fourth carbon (C4) is connected to the third.

### Step 4: Assign the Double and Triple Bond Positions
- The double bond is between C1 and C2 (1-ene).
- The triple bond is between C3 and C4 (3-yne).

### Step 5: Combine the Names
Combine the names of the double bond and triple bond with the base name of the longest carbon chain. The base name for four carbons is "butane." Since we have a double bond at C1 and a triple bond at C3, the IUPAC name becomes:
- But-1-ene (for the double bond)
- But-3-yne (for the triple bond)

### Final IUPAC Name
Thus, the complete IUPAC name for vinyl acetylene is **but-1-ene-3-yne**.

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