1. Esters and Esterification

2. C11-5-20 FUNCTIONAL GROUPS Vocabulary & Concepts Esterification
OUTCOME QUESTION(S):
C FUNCTIONAL GROUPS
Name and write structural models for and name alkyl
halides.
Name and write structural models for common alcohols
and describe uses.
Name and write structural models for common acids
Name and write structural models for common esters
and investigate importance.
Vocabulary & Concepts
Esterification

4. Esters account for some natural and artificial flavours and odors
The functional group of esters is the ester group.
Made up of two smaller functional groups
General formula: R–COOR’
R - hydrocarbon chain from the acid
R' - hydrocarbon chain from the alcohol
carbonyl group O C R
Esters account for some natural and artificial flavours and odors R'
alkoxy group
made by combining carboxylic acid and alcohol

6. O CH3CH2-C \ O-CH2CH2CH3 // Properties of Esters: alcohol acid
Polar covalent: < 5C are soluble in water
Strong IMF (dipoles) gives high bp/mp
But not as strong as alcohols and acids O C R δ- δ+ R'
The double-bonded oxygen part of the compound came from the acid…the other branch, the alcohol
CH3CH2-C O \
O-CH2CH2CH3 //
alcohol
acid

7. When you analyze the compound left to right, the acid is always first
Naming Esters
Identify the acid part of the compound.
Change acid ending from – oic acid to – oate
2. Identify the alcohol part of the compound.
Change alcohol name into a branch – yl
Written as two names
When you analyze the compound left to right, the acid is always first
acid
alcohol
CH3CH2CH2CH2COOCH2CH3 5 4 3 2 1 1 2
ethyl
pentanoate

8. Esters are complex enough…
Name the following compounds:
Esters are complex enough…
we won’t add branches HC
OCH2CH3 O
ethyl methanoate
rum
acid
CH3C – OCH2CH2CH3 O
acid
alcohol
alcohol
propyl ethanoate
pear
acid
alcohol
CH3CH2CH2COOCH2CH2CH2CH2CH3
pentyl butanoate
peaches

9. Draw the following compounds:
Draw the acid first HC
OCH3 O
methyl methanoate
acid
alcohol
H3C – C – OCH2CH2CH2CH3 O
butyl ethanoate
acid
alcohol
CH3CH2CH2CH2CH2COOCH2CH2CH3
propyl hexanoate
acid
alcohol

10. Making Esters: Esterification
Esterification is a reversible reaction
CH3CH2-C O \ OH //
CH3CH2-C O \
O-CH2CH2CH3 //
acid
ester
de esterification reaction + +
H2O
CH3CH2CH2OH
water
alcohol
This is our first look at organic reactions – there are more coming

11. CH3-C O H CH3-C O H HO-CH3 O-CH3 O H
Esterification between ethanoic acid and methanol:
Ester
(methyl ethanoate)
CH3-C O H
CH3-C O + H
HO-CH3
O-CH3 O H
Ethanoic acid
Methanol
The key here is to
write the alcohol “backwards”
to help visualize water leaving…
water

12. Write the esterification reaction for the reaction between pentanoic acid and 1-butanol.
CH3CH2CH2CH2-C O \ OH //
water
Pentanoic acid
HOH + +
CH3CH2CH2CH2-C O \
O-CH2CH2CH2CH3 //
HOCH2CH2CH2CH3
1-butanol
butyl pentanoate

13. Draw this esterification ALL in condensed formula…
Write the esterification reaction for the reaction between butanoic acid and methanol.
water
CH3CH2CH2COOH
butanoic acid
HOH + +
HOCH3
CH3CH2CH2COOCH3
methanol
methyl butanoate
Draw this esterification ALL in condensed formula…

14. Consider the alcohol propane-1,2,3-triol (glycerol)
An ester at each hydroxyl group creates a tri-ester
Called triglyceride – the main constituent of fat
H2C–OOC(CH2)14CH3
HC–OOC(CH2)14CH3
H2C–OH
HC–OH
HOOC(CH2)14CH3
Depending on the number of double-bonds in the acid chains that create the tri-ester, triglycerides can be saturated, mono-unsaturated or polyunsaturated.

15. C11-5-20 FUNCTIONAL GROUPS Vocabulary & Concepts Esterification
CAN YOU / HAVE YOU?
C FUNCTIONAL GROUPS
Name and write structural models for and name alkyl
halides.
Name and write structural models for common alcohols
and describe uses.
Name and write structural models for common acids
Name and write structural models for common esters
and investigate importance.
Vocabulary & Concepts
Esterification