A conjugated carbonyl group has a
Examples of unconjugated carbonyl compounds are propanal and propanone.
Typical conjugated (or α,β-unsaturated) carbonyl compounds are propenal
In addition to a normal
It can be attacked by nucleophiles at either the β-carbon or the carbonyl carbon.
Note that the product of 1,4-addition is an enol that will tautomerize to the more stable carbonyl compound.