1. Review ketone aldehyde : : Nucleophilic addition : - C=O very polar O+ -
C=O
very polar
Nucleophilic addition - O C : +
H-Nu H Nu O C H Nu +
H-OH
H-OR
H-NH2 + -

2. Nucleophilic addition
C O-H R
O-H
C O R .. H
C = O R .. H+
C = O R ..
+ H+ H H+
hydrate or diol
C O R .. H C R
O-H
O-R
+ H+ +
H-OH O .. H R .. O H N H ..
C = O R .. +
H-OR
hemi-ketal C R
O - H
N - H2
+ H+ C R N H
+ H2O +
H-NH2
Schiffs base

3. Addition of alcohol H C O CH3 H3C H C O H3C H+ + CH3OH H OCH3 ketone
hemi-
ketal
unstable
aldehyde
+ alcohol =
hemi-
acetal
unstable

4. Nucleophilic substitution .. .. hemi - acetal condensation reaction
H3C H OH
O - CH2 - CH3
O - CH2 - CH3 H .. .. H+ C
H3C H OH
O - CH2 - CH3 H+ ..
OH - CH3 - CH2 .. .. +
H2O
hemi -
acetal C
H3C H
O - CH2 - CH3
+ H+
aldehyde
alcohol +
alcohol
acetal +
condensation reaction
hemi-acetal + alcohol
acetal + H2O

5. acetal
propanal +
2 equivalents ethanol
stable
hemi-
ketal
2-butanone +
1 equivalent methanol
unstable

6. .. .. + cyclohexan one ethane diol .. .. ketal hemi-ketal H+ H + H2O

7. Carboxylic acids [O] [O] 1o alcohol aldehyde carboxylic acid methanol
methanal
methanoic acid
H-bond acceptor -
very high b.p.
H-bond donor - +
2 H-bonds / molecule

8. Carboxylic acids Nomenclature 1. Carboxyl group (COOH) always C1
2. Family name is longest C chain with COOH
3. Suffix is “-oic acid”
4. Carbonyl groups (C=O) called “oxo”
Hydroxy groups (OH) called “hydroxy”

9. Carboxylic acids 2-ethyl butan oic acid 2-ethyl 4-hydroxy 2-ethyl-
CH3 – CH2 – CH – C
CH2 – CH3 O OH 4 3 2 1
2-ethyl
butan
oic acid O
CH3 – CH2 – CH – CH2 – CH – CO2H OH
CH2 – CH3
2-ethyl
4-hydroxy 6 5 4 3 2 1
2-ethyl-
4-hydroxy
hexan
oic acid
2-ethyl-
4-oxo
hexan
oic acid
add [O]

10. Carboxylic Acids Chemical properties = = OH C=O + Bronsted acid
H+ donor HA
H+ + A- H+ +
weak acids, small dissociation
Ka = [A-] [H+]
Ka  1 x 10-5
pH  2.5 for 1M
[HA]

11. Carboxylic Acids H+ + H+ + -
resonance structure
anion stabilized

12. Carboxylic Acids - acidity also affects solubility soluble
short chain acids
H-bonding
long chain acids
insoluble
benzoic acid
LDF -
add a strong base (OH-)
soluble
ion-dipole

13. Reactions Acid-base reactions: + NaOH octanoic acid insoluble
sodium octanoate + water
soluble

14. Reactions Reduction: 5-oxo hexanoic acid 1,5- hexanediol 5-hydroxy
LiAlH4 6 5 4 3 2 1
5-oxo
hexanoic acid
1,5-
hexanediol
H2/ Pt
NaBH4
5-hydroxy
hexanoic acid