Figure 9.15. Nucleophilic Acyl Substitution: Anhydride to Carboxylic AcidsTRANSESTERIFICATION
Alcohols can act as nucleophiles and displace the esterifying group on an ester. This process is called
transesterification. In this reaction, one ester is simply transformed to another, as shown in Figure
9.16.
Figure 9.16. Nucleophilic Acyl Substitution: Transesterification
Different alcohol chains are swapped into and out of the esterifying group position.HYDROLYSIS OF AMIDES
Amides can be hydrolyzed under highly acidic conditions via nucleophilic substitution. The acidic
conditions allow the carbonyl oxygen to become protonated, making the molecule more
susceptible to nucleophilic attack by a water molecule. The product of this reaction is a carboxylic
acid and ammonia. This should be no surprise because this is the reverse of the condensation
reaction by which amides are formed. This reaction is shown in Figure 9.17.