[tiny101]

Hi there,

if H2SO4 (along with heat) is added to 2-methyl-2-pentanol, what would the resulting product be?

I have not dealt with reactions that add sulfuric acid to a compound that isn't an alkene/alkyne before. I was thinking that the OH would be displaced, and that the OSO2OH would replace it... but I can't really reason why that would happen. Further, the heat that's added made me suspect it might be an elimination reaction too.

Any guidance would really be greatly appreciated.

Thanks in advance.

[Yggdrasil]

How good of a nucleophile is OSO2OH?  If you consider the stability of all the possible products resulting from substitution or elimination reactions, which ones are the most stable?

[a student]

I think you will have a carbocation as an intermediate in your reaction and then if you don't have any good nucleophile in the medium of reaction your carbocation will have to do a rearrangement to it's most stable structure that can be an alkene or may be another carbocation which is more stable than the first carbocation which I have mentioned before.

[Yggdrasil]

Carbocations genereally won't be the final product of a reaction because they aren't stable at all and exist only as short-lived reaction intermediates.  Yes, carbocations can rearrange to more stable carbocations, but those more stable carbocations will eventually react with a nucleophile or perform an elimination reaction in order to fill the carbocation's octet.

However, I do agree that an E1 reaction would occur to form an alkene.  Now, the question is, where is the preferred position for the double bond?

[a student]

the most stable alkene is the one with more substituent so I think the hydrogen of CH2 must be eliminated.

[Yggdrasil]

Correct.  Your final product would be 2-methyl-pent-2-ene.