CHEM 130 Lecture Notes - Lecture 6: Molecular Orbital Diagram, Lone Pair, Leaving Group
Document Summary
Not all carboxylic acid derivatives are equally reactive. We can list the common carboxylic acid derivatives in a hierarchy" of reactivity, with the most reactive at the top and the least reactive at the bottom. Transformations are always possible moving down the hierarchy. All of these derivatives will react with water to form carboxylic acids, but at very different rates. Hydrolysing an amide requires boiling in 10% naoh or heating overnight in a sealed tube with concentrated hcl. Amides are the least reactive towards nucleophiles because they exhibit the greatest degree of delocalization. Esters are similar but, because the oxygen lone pairs are lower in energy, the effect is less pronounced. The greater the degree of delocalization, the weaker the c=o bond becomes. Amides react as electrophiles only with powerful nucleophiles such as ho . Acid chlorides, on the other hand, react with even quite weak nucleophiles: neutral roh, for example.
