The correct answer is option 2. Dienes.
Let us break down the terms and their meanings:
1. Terpenes:
Terpenes are a class of compounds derived from isoprene units. They often have a characteristic structure composed of multiple isoprene units, and they can have various functional groups. Terpenes may contain multiple double bonds, but the term "terpene" encompasses a broader range of structures.
2. Dienes:
Dienes are hydrocarbons that contain two double bonds. They are a specific type of compound with a distinctive structural feature – exactly two carbon-carbon double bonds.
3. Trialkyne:
The term "alkyne" refers to a carbon-carbon triple bond. "Trialkyne" would imply three triple bonds. However, in the context of the question, where double bonds are mentioned, "tri-" would not be appropriate.
4. Dialkyne:
The term "alkyne" refers to a carbon-carbon triple bond. "Dialkyne" would imply two triple bonds. Again, this term is not suitable for compounds with exactly two double bonds.
Therefore, the correct term for compounds with exactly two double carbon-carbon bonds is **Dienes** (option 2). A common example of a diene is butadiene, which has two adjacent double bonds in its structure. |
