Concept:To determine the IUPAC name from a common name, deduce the structure first. The "vinyl" group is \( \text{-CH}=\text{CH}_2 \). Acetylene is \( \text{HC}\equiv\text{CH} \).
Solution:- Structure: Divinyl acetylene means two vinyl groups attached to an acetylene core: \( \text{CH}_2=\text{CH--C}\equiv\text{C--CH}=\text{CH}_2 \).
- Chain length: The longest continuous chain has 6 carbons (hexa).
- Numbering: Numbering from either side gives the double bonds at C1 and C5, and the triple bond at C3.
- Suffixes: According to IUPAC, "ene" comes before "yne". The main chain is a 1,5-diene, and a 3-yne.
- Combining them: hexa-1,5-dien-3-yne (or 1,5-hexadiene-3-yne).
Why other options are incorrect:Option A incorrectly uses "ene" twice. Option C misidentifies the molecule as having two triple bonds (diyne). Option D improperly places "hexyne" before "diene" violating standard IUPAC assembly order.
Quality & Fidelity Assurance:
Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.