See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1 - Identify the parent chain/ring: The compound is a cyclohexene ring, so the parent name is cyclohex-2-ene (the double bond is between C2 and C3). Step 2 - Identify the principal characteristic group: The carboxylic acid (CO2H) is the highest-priority group and defines C1, giving the suffix '-carboxylic acid' (since the COOH carbon is part of the ring, we use 'carboxylic acid' as a suffix). Step 3 - Number the ring: C1 bears the COOH group. Going around the ring to give the substituents the lowest possible locants: C2-C3 double bond, then at C4 is NO2 (nitro), at C5 is CN (cyano), at C6 is Cl (chloro). Step 4 - Assemble the name: List substituents in alphabetical order with their locants: 6-chloro (Cl at C6), 5-cyano (CN at C5), 4-nitro (NO2 at C4), parent cyclohex-2-ene, suffix carboxylic acid. Step 5 - Full name: 6-chloro-5-cyano-4-nitrocyclohex-2-ene-1-carboxylic acid, which matches the given answer (noting 'cyno' is a typographical shortening of 'cyano' in the answer key). No other regiochemical assignment gives lower locants, so this numbering is correct. Therefore, the correct answer is 6-chloro-5-cyno-4-nitrocyclohex-2-ene carboxylic acid.