IUPAC name of the following is `CH_2=CH-CH_2-CH_2-C-=CH`

Options

A. 1, 5-hexenyne
B. 1-hexene-5-yne
C. 1-hexyne-5-ene
D. 1, 5-hexynene

Answer

To determine the IUPAC name of the compound `CH₂=CH-CH₂-CH₂-C≡CH`, we will follow these steps:

### Step 1: Identify the longest carbon chain
The first step is to identify the longest continuous carbon chain in the compound. In this case, the longest chain consists of 6 carbon atoms.

### Step 2: Number the carbon chain
Next, we need to number the carbon chain. The numbering should be done in such a way that the double bond and triple bond get the lowest possible numbers.

From left to right:
1. C1: CH₂ (double bond)
2. C2: CH
3. C3: CH₂
4. C4: CH₂
5. C5: C (triple bond)
6. C6: CH

So, the numbering is as follows:
- C1: CH₂ (double bond)
- C2: CH
- C3: CH₂
- C4: CH₂
- C5: C (triple bond)
- C6: CH

### Step 3: Identify the types of bonds
In this compound, we have:
- A double bond between C1 and C2 (alkene)
- A triple bond between C5 and C6 (alkyne)

### Step 4: Assign locants to the bonds
The double bond is located at position 1, and the triple bond is located at position 5.

### Step 5: Write the IUPAC name
According to the IUPAC nomenclature rules, we combine the names of the alkene and alkyne with their respective locants. The name will be structured as follows:
- The longest chain has 6 carbon atoms, which corresponds to "hex".
- The double bond is at position 1, so we use "1-hexene".
- The triple bond is at position 5, so we add "5-yne".

Putting it all together, the IUPAC name of the compound is **1-hexene-5-yne**.

### Final Answer:
**1-hexene-5-yne**

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