See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1 - Identify the parent structure: The molecule contains a benzene ring directly attached to a carbonyl (C=O) group, making it an aryl ketone (also called a phenone). Step 2 - Count the carbon chain: Attached to the carbonyl carbon (on the side opposite the phenyl group) is a butyl chain: -CH2-CH2-CH2-CH3, which is four carbons long. Step 3 - Determine total carbons in the ketone: The carbonyl carbon plus the four-carbon butyl chain gives a five-carbon acyl group (pentanoyl). Step 4 - Apply IUPAC nomenclature: The compound is named as a pentan-1-one with a phenyl substituent at C1. The phenyl group is at position 1 (the carbonyl carbon end), giving the name 1-phenylpentan-1-one. Alternatively, it can be viewed as the phenyl ketone of butyl group (butyrophenone). Step 5 - Confirm: phenyl + C(=O) + CH2CH2CH2CH3 = 1-phenylpentan-1-one (5 carbons in the chain including the carbonyl carbon, phenyl at C1). Therefore, the correct answer is 1-phenylpentan-1-one.