Hydride shifts and methyl shifts can occur in organic chemistry reactions if there is a carbocation intermediate. While Markovnikov's rule places the carbocation on the more substituted of the 2 former sp2 (double-bound) carbon atoms, if there is an EVEN MORE substituted carbon nearby, you'll get a carbocation rearrangement.
These videos help you understand the logic behind the most common types of carbocation rearrangement, along with specific patterns to look for when deciding between a hydride shift or methyl shift, with examples included.
(watch this video or YouTube or view the transcript – coming soon)
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This is video 7 in the Alkene Reaction Mechanism series. Click to see the entire series