1. Esters

2. What are Esters?
Can be naturally occurring in plants and contribute to the _______________ of fruits and flowers.
Uses: artificial/natural flavouring in foods, perfumes, cosmetics, oils, etc.
Esters can be made in the lab (__________)
pleasing odours
synthetic

3. Has a carbonyl (C=O) group attached to an oxygen atom (bonded to an alkyl group) and as well another alkyl group.
General Formula:
-COO-

4. Esterification How an ester is formed
Done by reacting a ____________ with an _______ in presence of a catalyst (an acid) over heat
Small amounts of water is formed as well
carboxylic acid
alcohol

5. Naming Esters Form: (alcohol) (acid-anoate) Example: methylpropanoate
Drop –anol, replace with “yl”
Change from “-oic acid” to “-oate”
methylpropanoate
carboxylic acid
alcohol

6. Naming Esters Form: (alcohol) (acid-anoate) Example: propylethanoate
Drop –anol, replace with “yl”
Take parent name, add “anoate”
propylethanoate
carboxylic acid
alcohol

7. Naming Esters
Draw the esterification reaction between methanol and ethanoic acid

8. Naming Esters Example: React methanol with butanoic acid.
methylbutanoate

9. Drawing Esters
propylbutanoate

10. Drawing Esters
butylheptanoate

11. Example
Draw the esterification reaction between propanol and hexanoic acid
propylhexanoate

12. Properties of Esters Polar molecules (due to presence of O)
Lower melting points and boiling points than carboxylic acids and alcohols (they both have OH groups = stronger)
Smaller esters are gases (the ones you smell) and large esters are solids