See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1 – Identify the parent chain/ring: The structure shows a six-membered carbocyclic (cyclohexane) ring, so the parent name is cyclohexane. Step 2 – Identify the principal characteristic group: There are two oxygen-containing groups present: a carboxylic acid (–CO2H) and a ketone (C=O) within the ring. According to IUPAC priority rules, carboxylic acid has higher seniority than ketone, so –CO2H is the principal characteristic group and receives the suffix '-carboxylic acid'. Because the –COOH carbon is exocyclic (attached to the ring carbon), the suffix used is '-carboxylic acid' appended to 'cyclohexane', giving 'cyclohexane-1-carboxylic acid' with C1 being the ring carbon bearing –COOH. Step 3 – Number the ring: The carbon bearing the –COOH substituent is C1 (locant 1 is implied/assigned to give the ketone the lowest possible locant). The adjacent carbon in the ring that bears the ketone (=O) is C2. Step 4 – Name the ketone as a prefix: Since the carboxylic acid is the principal characteristic group, the ring carbonyl (ketone) is expressed as the prefix 'oxo-' at position 2. Step 5 – Assemble the name: Parent ring = cyclohexane; principal group suffix = -carboxylic acid at C1; prefix for ring ketone = 2-oxo. Full name: 2-oxocyclohexane-1-carboxylic acid. There are no other options to eliminate in this naming question; the systematic IUPAC name uniquely and unambiguously describes the structure shown. Therefore, the correct answer is 2-oxocyclohexane-1-carboxylic acid.