Question

Using resonance, select the most acidic protons in the hexane-2,4-dione molecule. The most acidic proton is the one that, upon removal, will yield the most stable conjugate base.
Check all that apply.
[Hexane-2,4-dione molecule with protons numbered as follows according to IUPAC nomenclature: protons on C1 are numbered 1 through 3, protons on C3 are numbered 4 and 5, protons on C5 are numbered 6 and 7, protons on C6 are numbered 8 through 10.]

Check all that apply.

Protons 1, 2, or 3
Protons 4 or 5
Protons 6 or 7
Protons 8, 9, or 10

Answer 1

Answer:

Protons 4 or 5 are most acidic.

Explanation:

As mentioned there are four types of hydrogen in Hexane-2,4-dione.

The numbering are shown in the figure for your better understanding.

As shown in the figure if we remove the proton from carbon number 3 (protons number 4 or 5), it will result in formation of a carbanion. This carbanion is stabilized due to presence of -I group oxygen and there is possibility of resonance (as shown).

Thus protons 4 or 5 are most acidic.