See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1 - Identify the ring: The structure shows a five-membered carbocyclic ring, i.e., a cyclopentane-based ring. Step 2 - Identify the degree of unsaturation within the ring: There are two double bonds visible in the ring, making it a cyclopentadiene framework. Step 3 - Locate the substituent: A hydroxyl group (-OH) is attached to the carbon that is NOT part of either double bond, i.e., the sp3 carbon. In a cyclopentadiene ring with double bonds at positions 2,3 and 4,5, the sp3 carbon is at position 1. Step 4 - Apply IUPAC nomenclature rules: a. Parent chain/ring: cyclopentane -> cyclopenta (five-membered ring). b. Two double bonds: indicated by 'dien' with locants 2,4 (cyclopenta-2,4-diene). c. Principal characteristic group: -OH (alcohol), indicated by '-ol' suffix, located at C1. d. Numbering: The carbon bearing -OH gets the lowest possible locant (1), and the double bonds are then at C2-C3 and C4-C5, giving locants 2 and 4. Step 5 - Compile the name: cyclopenta + 2,4-dien + 1-ol = cyclopenta-2,4-dien-1-ol. Step 6 - Verification: The -OH group at C1 is on an sp3 carbon, two conjugated double bonds span C2=C3 and C4=C5, consistent with the drawn structure. Therefore, the correct answer is cyclopenta-2,4-dien-1-ol.