Explain why the hydrogens of the CC-8 methyl group are more acidic than those of the CC-7 methyl group in the FAD moiety. Check all that apply.

A. When a proton is removed from the methyl group at CC-8, the electrons left behind can be delocalized onto the nitrogen at the 5-position or onto the nitrogen at the 10-position.

B. When a proton is removed from the methyl group at CC-8, the electrons left behind can be delocalized onto the nitrogen at the 1-position or onto the nitrogen at the 3-position.

C. When a proton is removed from the methyl group at CC-8, the electrons left behind can be delocalized onto the oxygen at the 2-position or onto the oxygen at the 4-position.

D. When a proton is removed from the methyl group at CC-7, the electrons left behind can be delocalized only onto carbons.

E. When a proton is removed from the methyl group at CC-7, the electrons left behind cannot be delocalized.

The hydrogens of the CC-8 methyl group in the FAD moiety are more acidic than those of the CC-7 methyl group due to the delocalization of electrons. When a proton is removed from the methyl group at CC-8, the electrons that are left behind can be delocalized onto the nitrogen at the 5-position or onto the nitrogen at the 10-position. This resonance stabilization of the negative charge on the carbon atom makes the hydrogens more acidic. On the other hand, when a proton is removed from the methyl group at CC-7, the electrons that are left behind can only be delocalized onto carbons, which does not provide as much stabilization.

MinkaKelly MinkaKelly · Answer 2 · 2024-04-20T09:10:20-04:00

Final answer:

The hydrogens at the CC-8 position in FAD are more acidic due to the electron delocalization onto nearby nitrogens when a proton is removed, this leads to increased stability of the conjugate base. In contrast, the hydrogens at the CC-7 position lack this delocalization, making them less acidic.

Explanation:

The hydrogens of the CC-8 methyl group in FAD are more acidic than those of the CC-7 methyl group because of the potential for electron delocalization upon deprotonation. Specifically, statement a) is correct: When a proton is removed from the methyl group at CC-8, the electrons that are left behind can be delocalized onto the nitrogen at the 5-position or onto the nitrogen at the 10-position. This delocalization stabilizes the conjugate base, making the removal of a proton more favorable, and thus the hydrogen more acidic. On the other hand, statement e) accurately describes the methyl group at CC-7: When a proton is removed from this methyl group, the electrons that are left behind cannot be delocalized, which results in less stabilization of the conjugate base and therefore a lower acidity compared to the protons at the CC-8 position.