See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1 - Identify the ring size: Count the number of carbon atoms in the ring. The structure shows an eight-membered ring, so the parent name is 'cyclooctane' (cyclo + oct for 8 carbons). Step 2 - Identify the functional group: The two parallel lines at the top of the ring represent a carbon-carbon triple bond (alkyne). This is indicated by the two lines (double-bond-like notation) shown at the top of the ring structure, which in context of an alkyne within the ring means a triple bond between two adjacent ring carbons. Step 3 - Combine the parts: For a cyclic compound containing a triple bond, the suffix '-yne' replaces '-ane'. An eight-membered ring (cyclooctane) with one triple bond becomes cyclooctyne. Step 4 - Verify: Cyclooctyne is the smallest stable cyclic alkyne; the eight-membered ring provides just enough flexibility to accommodate the linear geometry required by the sp-hybridized carbons of the triple bond. No locant is needed because there is only one triple bond and by convention it is placed at position 1. Therefore, the correct answer is cyclooctyne.