IUPAC and NomenclaturemediumSUBJECTIVE

See imageIUPAC and Nomenclature Chemistry Question

Question

See image

Chemistry diagram for: See image
Answer: (5E)-2-BROMO-3-CHLOROHEPT-5-EN-1-OL

💡 Solution & Explanation

Step 1 – Identify the parent chain. The molecule contains a hydroxyl group (–CH2OH), two halogens (Br and Cl), and an internal double bond. Counting the longest carbon chain that includes all principal functional groups and the double bond: C1(CH2OH)–C2(CHBr)–C3(CHCl)–C4(CH2)–C5(CH=)–C6(=CH)–C7(CH3). That gives a 7-carbon chain, so the parent is heptane → hept-5-en-1-ol (numbering from the OH end to give the principal characteristic group the lowest locant). Step 2 – Number the chain. Starting from the CH2OH end as C1: C1=CH2OH, C2=CHBr, C3=CHCl, C4=CH2, C5=CH, C6=CH, C7=CH3. The double bond is between C5 and C6, giving hept-5-en-1-ol. Step 3 – Assign substituent locants. Bromine is on C2, chlorine is on C3. Name so far: 2-bromo-3-chlorohept-5-en-1-ol. Step 4 – Assign E/Z geometry at the double bond (C5=C6). At C5: substituents are the C4 chain (higher priority) and H. At C6: substituents are C7 (CH3, higher priority) and H. In the drawn structure the double bond shows the two higher-priority groups (C4-chain and CH3) on opposite sides of the double bond → E configuration. Therefore the double bond is (5E). Step 5 – Compile the full IUPAC name: (5E)-2-bromo-3-chlorohept-5-en-1-ol. No alternative options are given in this question, but any name with Z geometry, wrong locants, or wrong parent chain length would be incorrect. Therefore, the correct answer is (5E)-2-bromo-3-chlorohept-5-en-1-ol.

💬
Still have doubts about this question?
Send it to our AI chemistry tutor on WhatsApp — gets answered in minutes
Ask on WhatsApp →

Practice 22,000+ questions like this

AI-adaptive practice, video lectures, and full JEE Advanced Chemistry content — all in one place.

JEE Advanced · JEE Mains · NEET · IChO · AP Chemistry