Crotonaldehyde contains an alkene group and an aldehyde group. Mesityl oxide contains an alkene group and a ketone group. Both crotonaldehyde and mesityl oxide can be prepared by aldol condensation.
Carbonyl compounds are aldehyes and ketone. Their active group is C=O and we are going to prepare crotonaldehyde and mesityl oxide from carbonyl compounds.
Acetaldehyde reacts with dilute NaOH and aldol is given as the product. Aldol compound is heated alone or heated with I2 (behaves as a catalyst) will give crotonaldehyde as the product.
Acetone reacts with dilute NaOH Aldol is given as the product. Aldol compound is heated alone or heated with I2 as a catalyst will givemesityl oxide as the product.