Ring expansions occur as a carbocation rearrangement when an unstable cycloalkane is near a carbocation. You will come across ring expansion mechanisms during alkene reactions and later in SN1 and E1 reactions.
They key is to recognize when a ring is unstable, and the type of rearrangement that will help it become more stable. But don’t stop there. Ring expansions may be followed by a 1,2-hydride or 1,2-methyl shift.
The video below takes you through a tricky reaction mechanism taken from a students actual exam.
(Watch this video on YouTube or read the transcript coming soon)
Watch the previous video: Hydride Shift Methyl shift mechanism
Watch next video: Oxymercuration-Demercuration Reduction
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