Transcript Alkanoic acids and Esters

Alkanoic acids and Esters
Intermediate 2 Chemistry
Unit 2(b)(c)
Examples
Examples
Examples
Functional group
O
The carboxyl group
C
O
-COOH
H
Naming
• As with other organic molecules, except
ending is –anoic acid.
H
H
H
H
H C
C
C
C
H
H
H
H C
H
H C
H
H
CH 3
O
C
O
H
CH 3CH CH 2 CH CH 2 COOH
CH 3
Reactions
• React with alkanols to produce esters.
O
R
+
C
O
O
R1
H
H
O
R
O
+
C
O
ESTER
R1
H
H
Producing esters
Alkanol + Alkanoic acid
Ester + Water
• Because water is produced, this is called
a condensation reaction.
Specific example
H
H C
H
O
C
O
+
H
H
O
H
H
C
C
H
H
H
H
H
C
H
O
C
O
H
H
C
C
H
H
H+
O
H
• The –OH is removed from the ACID
• The –H is removed from the ALCOHOL
Using SSF:
CH3CH2CH2OH
+
HOOCCH2CH3
CH3CH2CH2OOCCH2CH3
• The C with H atoms attached is from the alcohol
• The C without H atoms attached is from the acid
H
• Use structural formulae to illustrate the
reaction of:
– Methanol with butanoic acid;
– Propanoic acid with ethanol.
Naming esters
• 1st part of name comes from the alkanol
– e.g. methanol produces methyl-, ethanol
produces ethyl- etc...
• 2nd part of name comes from alkanoic acid
– e.g. methanoic acid produces –methanoate,
ethanoic acid produces –ethanoate etc...
Practice
• Name the esters produced from...
– Butanol and pentanoic acid
– Heptanoic acid and ethanol
• Name the alkanols and alkanoic acids
used to produce...
– Pentyl butanoate
– Methyl octanoate
The reverse reaction
• The formation of esters is a reversible
reaction.
• This means that an alkanol and alkanoic
acid can be produced from an ester.
Ester + Water
Alkanol + Alkanoic acid
This breakdown using water is called a “hydrolysis” reaction.
H
H
C
H
O
C
O
H
H
C
C
H
H
H
H
CH3COOCH2CH2CH3
H
C
H
O
H
C
O
H
Ethanoic acid
H
H
C
C
H
H O
H
Ethanol
CH3COOH
CH3CH2CH2OH
Ethanoic acid
Propan –1- ol
H
H
H
C
C
H
H
O
C
O
H
H
H
H
C
C
C
C
H
H
H
H
H