Rank the following compounds from most reactive to least reactive toward nucleophilic addition:

The presence of the electron-withdrawing group increases the reactivity towards the addition while the presence of the electron-donating group decreases the reactivity of the compound towards nucleophilic addition. Benzaldehyde does not favor nucleophilic addition reaction due to resonance stabilization. The polarity of the carbonyl group is in benzaldehyde which is reduced due to the resonance making it less reactive in nucleophilic addition reactions.

Among the following compounds, para nitro benzaldehyde is more reactive towards nucleophilic addition reaction due to the presence of EWG followed by benzaldehyde and anisaldehyde. The least reactive one is isopropyl benzaldehyde due to the presence of EDG.

The order of reaction from most reactive to least reactive is as follows:

Most reactive least reactive

Order of reaction