Which of the following compounds is most reactive towards nucleophilic attack at the carbonyl carbon?

Step-by-step solution

The reactivity of a carbonyl compound towards nucleophilic attack depends on the magnitude of the positive charge (electrophilicity) on the carbonyl carbon. This is influenced by the inductive (-I) and resonance (+R) effects of the attached groups. In acetyl chloride ( CH₃COCl ), the chlorine atom exerts a strong -I effect and a very weak +R effect (due to ineffective 2p-3p orbital overlap). This strongly withdraws electron density, making the carbonyl carbon highly electron-deficient and very susceptible to nucleo