What is pulling off this hydrogen? (Pic inside)

[Cofo]

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So...at the beginning of the reaction when the pi bond from the nucleophile attacks one of H2SO4's hydrogen atoms...H2SO4 becomes a conjugate base HSO4^-. Hence, I am inquiring as to if HSO4^- (a conjugate base now, not an acid) is what deprotonate's the Hydrogen that I have referenced in my drawing.

I was just making sure of the mechanism, and was hoping the conjugate base HSO4^- was responsible for pulling that hydrogen off, to make the OCH3 be the only thing left. Can you confirm this? If I am wrong, please tell me what is pulling off that hydrogen. Thanks!

 

[molar3]

eh! your pic is confusing haha but.....i think that the H2so4 is just acting as an acid, and any acid will deprotonate the H . so initially the ch3OH gets attached, but the "acid" aka h2so4 will get rid of the Hydrogen, leaving u with ch3O
also youre reacting an alcohol , and alone the alcohol wont do anything, nothing will react, so it NEEDS to be acid catalyzed
imo.

 

[Cofo]

eh! your pic is confusing haha but.....i think that the H2so4 is just acting as an acid, and any acid will deprotonate the H . so initially the ch3OH gets attached, but the "acid" aka h2so4 will get rid of the Hydrogen, leaving u with ch3O

Acids are proton donors, not proton acceptors. If an acid deprotonate's a carbon (the acid removes a hydrogen from the carbon)...then the acid just accepted a proton...which is not what an acid does. So...at the beginning of the reaction when the pi bond from the nucleophile attacks one of H2SO4's hydrogen atoms...H2SO4 becomes a conjugate base HSO4^-. Hence, I am inquiring as to if HSO4^- (a conjugate base now, not an acid) is what deprotonate's the Hydrogen that I have referenced in my drawing. Anyone else know what is going on?

 

[FROGGBUSTER]

yup, you got it, HSO4- takes it.

 

[Cofo]

yup, you got it, HSO4- takes it.

hell yeah! haha this makes me so happy I was correct...I didn't do so well in my orgo classes, but I'm understanding it now....so much easier than I thought! Thank you FROG! 👍

 

[rockclock]

.

 

[rockclock]

FYI, bisulfate is the conjugate base of a strong acid, and, hence, not strong enough to pull that proton...usually mechanisms just BS that step since the reality is more complicated. It won't come up on the DAT for that reason.

 

[HannibalLecter]

Confirming that HSo4- indeed does take off the hydrogen off the alcohol thus itself being more stable and making the alcohol more stable as well.

 

[seattlesun]

I believe that the double bond acts as a nucleophile attracting a H+ to the terminal carbon. Now there will be a carbocation on a 2* carbon. Rearrangement will bring the carbocation + charge on the 3* carbon, this being the most stable carbocation that the molecule is capable of. This 3* carbon will experience the attack from the alcohol, and voila we got our product!