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can someone please explain this better than the sentence-long answer in the back of the book? thanks!
destroyer ochem #119 - hydride shift??
- Thread starter Kneecoal
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Can you post the question?
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the hydrogen on carbon next to the carbocation can shift to where the carbocation's carbon is. it does this so that it can form a more substituted, stable carbocation (3>2>1). now the positive charge will be where the hydrogen once was.
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Hydride or Methyl shifts occur in case of SN1/E1 reactions. Why?
The main reason is to convert primary and secondary carbocations to tertiary carbocations, which tend to be more stable intermediates (Note: A more stable intermediate lowers the Ea of the reaction, causing the reaction to proceed faster and more efficiently).
Such shifts usually occur, when you have branching next to a primary or a secondary carbon bearing the halogen (leaving group). Consider the following example:
When X leaves, the result would be a secondary carbocation. However, the H on the adjacent C can shift on to the secondary C, producing a tertiary carbocation as the result.
The main reason is to convert primary and secondary carbocations to tertiary carbocations, which tend to be more stable intermediates (Note: A more stable intermediate lowers the Ea of the reaction, causing the reaction to proceed faster and more efficiently).
Such shifts usually occur, when you have branching next to a primary or a secondary carbon bearing the halogen (leaving group). Consider the following example:
When X leaves, the result would be a secondary carbocation. However, the H on the adjacent C can shift on to the secondary C, producing a tertiary carbocation as the result.
