which structure is more stable and which structure is more acidic,why?

[moan1223]

Obiviously, triethyl orthoformate is more acidic than ethnol. Because Triethyl orthoformate is an orthoester of formic acid and ethanol. So generally it's more acidic than ethanol. But I don't have some sort of reference. I can't it by googling,too.
But when both of them deprononated, the negative charge is on oxygen of triethyl orthoformate, while on carbon of ethnol.
1.According to rules learned from organic chemistry, the negative charge on a more electronegative atom(eg. O) is more stable than on less electronegative atom(eg. C).
2.According to rules that when the conjugate base is more stable, then the conjugate acid is more acidic.
So,we can conclude that triethyl orthoformate is less acidic than ethnol.

Seemingly contradictory? I don't know where am I wrong.

Edited June 3, 2013 by moan1223

[Brett Nortje]

Obiviously, triethyl orthoformate is more acidic than ethnol. Because Triethyl orthoformate is an orthoester of formic acid and ethanol. So generally it's more acidic than ethanol. But I don't have some sort of reference. I can't it by googling,too.

But when both of them deprononated, the negative charge is on oxygen of triethyl orthoformate, while on carbon of ethnol.

1.According to rules learned from organic chemistry, the negative charge on a more electronegative atom(eg. O) is more stable than on less electronegative atom(eg. C).

2.According to rules that when the conjugate base is more stable, then the conjugate acid is more acidic.

So,we can conclude that triethyl orthoformate is less acidic than ethnol.

 

Seemingly contradictory? I don't know where am I wrong.

What is it you are trying to do? how will you hope it works?

[spirochete27]

First of all, I would question your logic explaing why triethyl orthoformate is supposedly more acidic than ethanol. Most carboxylic acids are more stable than most alcohols, but here we're dealing with a type of ester of a carboxylic acid. Totally different situation. I could not find the pKa of triethyl orthoformate from a google search but I doubt it's more acidic than ethanol. Somebody please correct me if they can find the pKa anywhere.

 

Also, there are more factors that effect acidity than just the one you named. You're correct that more acidic molecules have more stable conjugate bases, but there are many factors that effect the stability of a conjugate base.