Quick question about Elimination Reaction.

[potbelly]

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Hi all,

I just have a quick question about Elimination Rxn.

Can Hydride and Methyl shift occur in both E1 and E2? Or just E1?

 

[iwannabadentist]

i would say it occurs only in E1 because there is no cation formation for E2.

 

[Sublimation]

By looking at the mechanism the E2 mechanism occurs in one step. There is no intermediate. In the E1 mechanism you do have an intermediate that is subject to a rearrangement (methyl or hydride shift)

 

[potbelly]

Thanks🙂

 

[miedvied]

E1 forms a carbocation, allowing for the shift. E2 is a concerted mechanism - due to lack of electron contribution from branching, you'll never see a separate carbocation forming intermediate, and therefore no chance for a shift.