reaction mechanisms: substitution vs elimination

[santal0l]

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Why is it that the major product formed is through an Sn1 mechanism rather than an E1 mechanism?

I thought that if the reaction took place in increased temperature (the delta symbol means increased temperature right?), it would favor elimination rather than substitution, plus doesn't that Sn1 reaction have a lot of steric hindrance from the ethyl group which would slow down the rate of Sn1 and cause Elimination over substitution.

Furthermore, one particular elimination product can be formed by either the non-rearranged or rearranged carbocation.

 

[Ottovon]

CH3OH is a weak nucleophile, not a weak base.

 

[DougTPR]

In general, purely E1 mechanisms are hard to come by.

A sure fire guarantee is acid catalyzed dehydration of alcohols.

The other option needs a stronger base while at the same time that base must not be sufficiently nucleophilic. There aren't many of these out there and alcohols are not in this category.

Most "E1" reactions are really SN1/E1 mixtures so they don't make for good MCAT question fodder in the end.