Nucleophilic Addition to the Carbonyl Group
The carbon of the carbonyl group is an electrophile. Thus it is susceptible to nucleophilic attack. During most addition reactions of alkenes, it is an electrophile that attacks the pi system. But in an addition reaction involving a carbonyl group, we see that the attack on the carbonyl carbon is made by a nucleophile. Think about why this is the case? One reason for this is the polar nature (due to electronegativity of the oxygen atom) of the carbonyl group. Furthermore, the resonance capability of the carbonyl group also enhances this type of reactive property. A generalized nucleophilic attack is shown below in Figure 22-1.