[chr147]

I am working on an addition mechanism problem, of an alcohol to an alkene to produce an ether.  The following pictures have the problem and the textbooks answer (Bruice, 7th edition Organic Chemistry). I am confused about the answer they have. They have the H+ nucleophile adding to the alcohol, and then the proton from the alcohol being added to the sp2 carbon of the alkene, even though in the textbook they mention that the H+ (from the acid catalyst) is added to the sp2 carbon of the alkene.

I worked it out adding the proton to the double bond of the alkene, and get a different looking mechanism, but same product. Did I do something wrong in my mechanism to get the same answer, or can you simply add the proton to either the alcohol or the alkene?

Thank you for your help. (I'm very new to these, my apologies if I made any errors trying to explain).

[mjc123]

You could add H⁺ directly to the alkene, but since alcohols are much more basic than alkenes, ROH is more likely to be protonated. If the acid is present in catalytic amounts, ROH₂⁺ will be the predominant labile-proton species, so the alkene is most likely to be protonated by ROH₂⁺.

[asmcriminal]