Which is the correct IUPAC name of the compound, $CH_3CH=CHC(Br) (CH_3)_2$?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 4-Bromo-4-methylpent-2-ene
To determine the IUPAC name, follow these standardized rules:
1. Identify the Longest Carbon Chain:
The longest continuous chain containing the double bond has 5 carbon atoms, making the parent alkane pentane. Since there is a double bond, the suffix is -ene.
2. Number the Chain:
Number the chain from the end that gives the double bond the lowest possible number.
- Numbering from left to right: The double bond starts at C2.
- Numbering from right to left: The double bond starts at C3.
- Therefore, we number from left to right.
3. Locate Substituents:
Using the left-to-right numbering:
- The double bond is at position 2.
- There is a Bromine atom (bromo) at position 4.
- There is a Methyl group ($-CH_3$) at position 4.
4. Assemble the Name:
Alphabetize the substituents (Bromo comes before Methyl) and combine them with the parent chain name.
- Substituents: 4-Bromo-4-methyl
- Parent: pent-2-ene
Final IUPAC Name: 4-Bromo-4-methylpent-2-ene