Complex sentence: The Perkin reaction is an organic reaction developed by William Henry Perkin that is used to make cinnamic acids i.e. α-β-unsaturated aromatic acid by the aldol condensation of aromatic aldehydes and acid anhydrides in the presence of an alkali salt of the acid.
Split into simpler sentences: The Perkin reaction is an organic reaction developed by William Henry Perkin that is used to make cinnamic acids. It gives an α, β-unsaturated aromatic acid by the aldol condensation of an aromatic aldehyde and an acid anhydride, catalyzed by an alkali salt of the acid.