[Rutherford]

How is called the rearrangement in the attached picture? At what conditions does it happen?

[discodermolide]

I suppose it may be similar to a Wagner-Meerwein rearrangement. Although this happens with carbocations and alkyl or aryl groups moving around the place.
http://en.wikipedia.org/wiki/Wagner–Meerwein_rearrangement
No idea of the mechanism

[Sophia7X]

Wait, is this really supposed to be an equilibrium?

Because in an SN1 mechanism, carbocation rearrangement can occur if it generates a more stable carbocation.



However, this carbocation rearrangement will take some time. So sometimes, the nucleophile is able to attack before the rearrangement occurs, and sometimes it will be able to attack after rearrangement occurs. So you can get a mix of both products.

[Rutherford]

Thanks for the replies. So, in every sN₁ reaction, I need to take into account that this type of rearrangement could occur.

[discodermolide]

Yes it could occur, have a look at the link I posted, that says it all, or most of it.

[Rutherford]

That's a bit over my level of understanding  .

[discodermolide]

It just shows the possibilities of carbocation rearrangements and discusses the classical/non-classical arguments.
Nothing hard in there. In fact I think this discussion is still ongoing.

[Rutherford]

Yes, but the bicyclo compounds scared me  .

[discodermolide]

The bicyclic compounds scare me too