The one giving maximum number of isomeric alkenes on dehydrohalogenation reaction is (excluding rearrangement):
Hydrocarbons · Class 11 · JEE Main Previous Year Question
The one giving maximum number of isomeric alkenes on dehydrohalogenation reaction is (excluding rearrangement):
- a
1-Bromo-2-methylbutane
- b
2-Bromopropane
- c✓
2-Bromopentane
- d
2-Bromo-3,3-dimethylpentane
2-Bromopentane
Step 1: Recall dehydrohalogenation (E2 elimination)
Dehydrohalogenation removes to form alkenes. The number of isomeric alkenes depends on the number of distinct -hydrogens available.
Answer: Option (c)
Key Points to Remember:
- Count distinct -carbons with H atoms to determine number of elimination products
- Geometric isomers (cis/trans) count as separate alkenes
- Quaternary carbons have no -H, so no elimination possible from that side
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