[RESOLVED] why is a 3˚ alpha carbon less acidic than a 2˚ alpha carbon?

[tdod]

thanks in advance!

for instance, in acetoacetic ester synthesis, a stronger base is necessary to produce a second alkylation of the alpha carbon, since the alkylated alpha carbon is less acidic.

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[ayocaptain628]

thanks in advance!

provide context of question pls

 

[tdod]

provide context of question pls

updated.

 

[chojin01]

thanks in advance!

yeah, need more context. If the alpha carbon has alkyl groups attached to it, then a tertiary alpha carbon would mean more electron donating groups therefore less acidic

 

[tdod]

nvm, i realized the acidity decreases b/c the resulting carbanion is destabilized by hyperconjugation of the new alkyl group.

 

[jaybird12]

I find it helpful to think of electron donating and electron withdrawing groups when ranking acidity. Alkyl groups are electron donating, and so the more alkyl groups bonded to a carbanion, the more unstable the carbanion is (so the conjugate base is not stable => conjugate base is going to act as a strong base to get rid of that extra lone pair of e- => original acid is not very acidic). If there were electron withdrawing groups attached, then the carbanion would be more stable and the acid more acidic.
It sounds like you understand though!