Which of the following has the most acidic hydrogen ?

Options

A. 3-hexanone
B. 2,4-hexanedione
C. 2,5-hexanedione
D. 2,3-hexanedione

Answer

B

Explanation

2,4-hexanedione (a 1,3-diketone) has the most acidic hydrogen. This is because the carbanion left after the removal of `H^(+)` is resonance stabilised in this case.
`{:(underset("2,4-Hexanedione")(CH_(3)-overset(O)overset(||)(C)-CH_(2)-overset(O)overset(||)(C)-CH_(2)CH_(3))overset(OH^(-))underset(-H_(2)O)rarrCH_(3)-overset(O)overset(||)(C)-overset(-)(C)H-overset(O)overset(||)(C)-CH_(2)CH_(3)),(" "CH_(3)-overset(O)overset(||)(C)-overset(-)(C)H-overset(O)overset(||)(C)-CH_(2)CH_(3)),(" "harrCH_(3)-overset(O^(-))overset(|)(C)=CH-overset(O)overset(||)(C)-CH_(2)CH_(3)),(" "harrCH_(3)-overset(O)overset(||)(C)-CH=overset(O^(-))overset(|)(C)-CH_(2)CH_(3)):}`