What is the difference between an ester and a carboxylic acid?
Both carboxylic acids and esters contain a carbonyl group with a second oxygen atom bonded to the carbon atom in the carbonyl group by a single bond. In a carboxylic acid, the second oxygen atom also bonds to a hydrogen atom. In an ester, the second oxygen atom bonds to another carbon atom.
Why do esters have lower vapor pressures than alcohols and carboxylic acids?
Because esters do not have hydrogen bonds between molecules, they have lower vapor pressures than the alcohols and carboxylic acids from which they are derived. Both carboxylic acids and esters contain a carbonyl group with a second oxygen atom bonded to the carbon atom in the carbonyl group by a single bond.
What happens when a carboxylic acid reacts with an alcohol?
When a carboxylic acid is reacted with an alcohol in the presence of a strong acid, which acts as a catalyst, an ester is formed along with a molecule of water. An example of this reaction is shown below where acetic acid reacts with isopentanol (3- methylbutanol) to form the ester isopentyl acetate and water.
What is a synthetic pathway to esters?
Other synthetic pathways to esters also exist. Acid chlorides react with alcohols to yield an ester and hydrochloric acid. A small amount of pyridine or other base is usually added to the reaction mixture to neutralize the resulting acid. Acid anhydrides can also react with alcohols to produce esters. Artificial flavors often contain esters.
Chapter 5 Carboxylic Acids and Esters