See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1: Identify the structure. The compound shown is: HOOC–CH(OH)–CH(OH)–COOH. It consists of two –COOH groups and two –OH groups on adjacent carbon atoms. Step 2: Determine the parent chain. The longest carbon chain including both carboxylic acid groups has 4 carbons (C1 through C4), where C1 and C4 are the carboxyl carbons, and C2 and C3 bear the hydroxyl groups. Step 3: Name the parent chain. A 4-carbon chain with carboxylic acid groups at both ends (positions 1 and 4) is named butane-1,4-dioic acid (analogous to succinic acid / butanedioic acid). Step 4: Add substituents. There are hydroxyl (–OH) groups at C2 and C3, giving the prefix '2,3-dihydroxy'. Step 5: Assemble the full name: 2,3-Dihydroxybutane-1,4-dioic acid. Step 6: Evaluate the options. - Option (a) '2,3-Dihydroxybutane-1,4-carboxylic acid' is incorrect because 'carboxylic acid' as a suffix used with locants 1,4 is not standard IUPAC nomenclature for a diacid of this type. - Option (b) '2,3-Dihydroxybutane-1,4-dioic acid' correctly names the compound: a 4-carbon chain with two carboxylic acid termini (dioic acid) and hydroxyl groups at C2 and C3. - Option (c) '1,2-Dihydroxyethane dicarboxylic acid' is incorrect; while this describes the same connectivity in an alternative substitutive sense, it is not the preferred IUPAC name since the –COOH groups are included in the principal chain rather than treated as substituents on a 2-carbon chain. Therefore, the correct answer is B.