Aromatic aldehydes undergo crossed-aldol condensation with ketones in the presence of silica sulfuric acid under solvent-free conditions to afford the corresponding <FONT FACE=Symbol>a, b</FONT>-unsaturated aldol products in excellent yields. The reagent is reusable for several times without any decrease in the yield of the reactions.
crossed-aldol condensation; silica sulfuric acid; solid phase; <FONT FACE=Symbol>a, b</FONT>-unsaturated carbonyls