why is the carbocation that forms doubly allylic?
electrophilic substitution of benzene Watch
- Thread Starter
- 28-12-2010 20:46
- Community Assistant
- Study Helper
- 28-12-2010 20:51
.. just the first stage (addition) removes the delocalised orbital, which previously extended over the whole ring to just over four carbon atoms, forming the carbocation.
This has to happen because the carbon to which the electrophile adds becomes sp3 leaving no 'p' orbital available for a molecular orbital.
The loss of the delocalised pi system destabilises the carbocation making elimination favoured, to restore the molecular orbital.