Determine the correct decreasing order of acidity for the underlined protons in the following compounds: (i) (ii) (iii)

Step-by-step solution

The acidity of the underlined protons depends on the stability of the conjugate base (carbanion) formed after the removal of an H^+ ion. In compound (iii), the underlined protons belong to an active methylene group flanked by two strongly electron-withdrawing carbonyl groups (one ester and one ketone). The resulting carbanion is highly stabilized by extended resonance over both carbonyl oxygen atoms, making it the most acidic. In compounds (i) and (ii), the carbanion is stabilized by resonance with only one carbony