JEE Main 2026 · 22 January · evening · Single correct · +4 / −1
The IUPAC name of the following compound is:
- (a) 2-bromo-5-methylhexylpropanoate
- (b) n-propyl-1-bromo-4-methylhexanoate
- (c) n-propyl-2-bromo-5-methylheptanoate
- (d) 2-bromo-5-methylpropanoate
Answer and solution
Answer (c) n-propyl-2-bromo-5-methylheptanoate
Solution
Chemistry ma’am · 4 steps
Split the ester at the single-bonded O: the alkyl side is named first, the acid side becomes the -oate.
- Split the ester. An ester R-COO-R' is named as alkyl alkanoate. The group on the oxygen, -CH₂CH₂CH₃, is the alkyl part, so the name starts with propyl (n-propyl).
- Longest acid chain. The carbonyl carbon is always C1 of the acid part. From C1, go through the CHBr carbon and two CH₂ groups to the branching carbon. Then turn down into the ethyl arm, not the single CH₃, because that gives the longer chain: 7 carbons, so the acid part is heptanoate.
- Place substituents. Bromine sits on the carbon next to the carbonyl, which is C2. The leftover CH₃ hangs on C5. Alphabetical order puts bromo before methyl: 2-bromo-5-methylheptanoate.
- So. The name is n-propyl 2-bromo-5-methylheptanoate, option (c).
The idea to keep. In an ester, the carbonyl carbon is C1 of the acid chain and must be in it. Then follow the longest path through the branches, which may bend round a corner of the drawing.
Answer from the NTA final answer key. Solution by PrepWiser.