Which statements about the compound shown are correct? Select all that apply.

AThe aromatic hydrogens ortho to the carbonyl groups are alpha hydrogens that can enolise.
BThe CHO group has no alpha hydrogen.
CIt has 3 hydrogens on carbons directly bonded to a carbonyl carbon.
DOnly the acetyl CH $_{3}$ group can be converted to an enolate.

Answer: B, C, D

The compound shown is 2-acetylbenzaldehyde. The acetyl carbonyl is bonded to a CH

_{3}

(3 H) and to a ring carbon; the CHO carbon is bonded only to a ring carbon, so the only alpha hydrogens are the 3 of the CH

_{3}

group. The ortho ring hydrogens are on carbons two bonds from a carbonyl carbon (beta to it, and part of an aromatic ring), so they cannot enolise.