Question

The IUPAC name of the following compound is

• A. 6-Ethyl-9-methyl-4-bromodec-5-en-7-ol
• B. 7-Bromo-2-methyl-5-ethyldec-5-en-4-ol
• C. 7-Bromo-5-ethyl-2-methyldec-5-en-4-ol
• D. 4-Bromo-6-ethyl-9-methyldec-5-en-7-ol

Hint:

Number the chain giving priority to functional groups like -OH and double bonds.

Answer 1

The Correct Option is C

Step 1: Identify the longest chain containing the double bond and alcohol group
The parent chain is decene (10 carbons) with a double bond at position 5 and an alcohol at position 4.
Step 2: Number the chain to give substituents the lowest possible numbers
Numbering from the end nearest to the OH group gives the substituents positions: bromo at 7, ethyl at 5, methyl at 2.
Step 3: Combine substituent names and positions
Hence the name: 7-Bromo-5-ethyl-2-methyldec-5-en-4-ol.