Do alkenes ever rearrange twice to get to the most stable carbocation?

[510586]

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Alkenes rearrange in SN1 reactions or when adding HBr if a more stable carbocation is possible. But is it possible for a carbocation to rearrange twice (1 degree to 2 degree to 3 degree) to get to the stablest carbocation? Or is that too many steps?

 

[DAT Destroyer]

Alkenes rearrange in SN1 reactions or when adding HBr if a more stable carbocation is possible. But is it possible for a carbocation to rearrange twice (1 degree to 2 degree to 3 degree) to get to the stablest carbocation? Or is that too many steps?

No.....You will not see this. In Advanced Organic Chemistry there are cases when you see multiple shifts.

Do a single shift to establish a better carbocation. Usually there is not enough time. A nucleophile is sure to attack. If you have interest in this, you can find examples in Advanced texts.

If for example, you worked in Magic Acid....SbF5-HOSO3F...this can occur; multiple shifts one after the other !!!!

These acids allow long-lived carbocations to survive long enough to rearrange to optimum stability.

Hope this helps on a GREAT QUESTION !!!!!

Dr. Jim Romano

 

[510586]

No.....You will not see this. In Advanced Organic Chemistry there are cases when you see multiple shifts.

Do a single shift to establish a better carbocation. Usually there is not enough time. A nucleophile is sure to attack. If you have interest in this, you can find examples in Advanced texts.

If for example, you worked in Magic Acid....SbF5-HOSO3F...this can occur; multiple shifts one after the other !!!!

These acids allow long-lived carbocations to survive long enough to rearrange to optimum stability.

Hope this helps on a GREAT QUESTION !!!!!

Dr. Jim Romano

Yea this helps a lot thank you so much as always!

 

[DAT Destroyer]

Yea this helps a lot thank you so much as always!

Always glad to help!

Dr. J

 

[510586]

Always glad to help!

Dr. J

I'll be going over all the stuff I found weird or didn't understand on odyssey today so there may be a bunch of questions haha

 

[DAT Destroyer]

I'll be going over all the stuff I found weird or didn't understand on odyssey today so there may be a bunch of questions haha

Let's get the "30" in Orgo!