An aldehyde/ketone in the presence of a base forms a carbanion at the $$\alpha$$-position which can react with a carbonyl group in an Aldol type of reaction. It can also react with an olefinic double bond which is activated by groups like CO, CN, $$\text{NO}_2$$ attached to the double bond. The latter reaction is an addition reaction across the double bond. Wieland-Miescher ketone is an important synthetic intermediate used to synthesize many compounds

The pair of starting materials suitable for preparation of Wieland-Miescher ketone through a base catalysed reaction is