Carbocation Rearrangements

Carbocation Rearrangements

Carbocations are carbon atoms that carry a positive charge. They are formed when a leaving group departs (see the SN1, SN2, E1 and E2 reaction!) or when an alkene acts as a nucleophile.

• carbocations that are more substituted are more stable (tertiary > secondary > primary >>> methyl)
• carbocations can also be stabilized by resonance (i.e. vinylic and allylic)

Carbocation Rearragements

Sometimes, carbocations will rearrange in order to produce a more stable form. This can happen a few different ways with two being the most common:

1. a 1,2-hydride shift
2. a 1,2-methyl shift