Question

Hydrochloric acid and hydrobromic acid react with both 3-methyl-2-butanol and 2-methyl-2-butanol to form halides or alkenes, while nitric acid reacts with the aromatic ring in 1,4-dimethoxybenzene. Why does sulfuric acid allow for the formation of the desired product in high yields?

1. The alcohols used in this lab cannot undergo elimination reactions, so using sulfuric acid cannot result in any side products. 2. Acetic acid in the solution prevents the formation of side products by acting as an electrophile, enhancing the activity of sulfuric acid 3. 1,4-dimethoxybenzene is a better nucleophile than the conjugate base of sulfuric acid, so alkylation takes place faster than elimination or substitution 4. The formation of a complex between sulfuric acid and 1,4-dimethoxybenzene allows for the rapid addition of alcohols to the aromatic ring without time for the generation of side products.

Answer 1

First to all, you need to put the whole reaction or experiment. I don't quite understand very well what are you trying to achieve here. What's the desired product? what reaction are you taking place? I need that data to better answer this,

Now, I could respond this question basing on the little information you provided and the options here, but at least I can give you a guide to answer it.

Option 1. This could not be the correct answer basically because both alcohols in here are secondary and terciary, and when they experiment a acid base reaction, the alcohols gets protonated and they can easily perform an elimination reaction, so, this option is discarted.

Option 3. The 1,4 - dimethoxybencene is very bulky substract, bulkier than H₂SO₄, the conjugate base of this compound is HSO₄^- so, it's a weak base, but it's sure a better nucleophile than dimethoxybencene, because it has a charge electron, that it can attack a nucleophile better than dimethoxybencene, the oxygens atoms in this molecule are too steric (one methyl in one side and the bencene on the other side) so this option can be discarted too.

Option 4. the reaction with H₂SO₄ and dimethoxybencene can be a sulfonation reaction, where the HSO₃ goes to the orto position in the bencene, so it does not form a complex here, so, in theory, this option can be discarted too. And I say in theory, because, this option is very related to the final products, but again, I don't know what reaction is this, and the final products.

Option 2. This option could be the correct one, because this acid can enhance the activity of any strong acid. But again, if you show the final product I can confirm this.

Hope this helps