Question

Explain the examples of functional derivative of carboxylic acid.

Answer 1

A functional derivative of a carboxylic acid is a substance formed by replacement of the acid by some other groups, $X$ such that it can be hydralyzed back to the acid.

By this definition, an amide, $RCON{H}_2$ but not a ketone, $RCO{H}_3$, it is a functional derivative of a carboxylic acid. Several derivatives of carboxylic acids are given on the images above.