See image — IUPAC and Nomenclature Chemistry Question

💡 Solution & Explanation

Step 1 (Identify the compound class): The structure contains a carbonyl group (C=O) bonded to an -OCH2CH3 (ethoxy) group, making it an ester. The ester is therefore an ethyl ester. Step 2 (Identify the parent acid chain): Counting the carbons in the acid portion: the carbonyl carbon is C1, then there are two more carbons (C2 and C3) before reaching the phenyl group. This gives a three-carbon (propanoic acid) backbone. Step 3 (Identify the substituent): A phenyl group (C6H5-) is attached at C3 (the beta carbon, or position 3) of the propanoate chain. Step 4 (Construct the IUPAC name): The parent acid is propanoic acid with a phenyl substituent at C3, giving 3-phenylpropanoic acid. The ester is formed with ethanol, so the full IUPAC name is ethyl 3-phenylpropanoate. Step 5 (Verification): The structure Ph-CH2-CH2-COO-CH2CH3 matches ethyl 3-phenylpropanoate perfectly — ethyl ester of 3-phenylpropanoic acid (also known as hydrocinnamic acid). Therefore, the correct answer is ethyl 3-phenylpropanoate.