1. of carbonyl group chemistry
An overview
of carbonyl group chemistry

2. CARBONYL GROUP sp2      sp2 sp2      sp2
C=O bond length A
C=C bond length A

3. CARBONYL GROUP ELECTRONIC STRUCTURE
Lone-pair electrons -
Lone-pair electrons
π-bond +
Carbon
or Hydrogen
Carbon
or Hydrogen

4. CARBONYL GROUP ORBITALS

5. POLARIZATION OF CARBONYL GROUP AND ITS REACTIVITY
Nucleophilic oxygen reacts
with acids and electrophiles - +
Electrophilic carbon reacts
with bases and nucleophiles

6. TYPES OF CARBONYL COMPOUNDS
ALDEHYDES
Hydrogen or carbon
cannot stabilize
negative charge and
therefore cannot act
as leaving group
KETONES

7. TYPES OF CARBONYL COMPOUNDS
Carboxylic acid
Carboxylic acid chloride
Carboxylic acid anhydride
Carboxylic acid ester
Carboxylic acid amide
Electronegative atom (oxygen, halogen, nitrogen) bonded to acyl group
R-CO- can stabilize a negative charge, therefore groups –OH, -Cl, -OCOR’,
-OR’, -NH2 can serve as leaving groups in substitution reactions.

8. TYPES OF CARBONYL COMPOUNDS
Cyclic acid anhydride
Cyclic ester
(lactone)
Cyclic amide
(lactam)

9. POLARITY OF CARBONYL COMPOUNDS
Type of carbonyl group
Dipole moment
(D)
HCHO
CH3CHO
(CH3)2CO
PhCOCH3
Cyclobutanone
CH3COOH
CH3COCl
CH3COOCH3
CH3CONH2
CH3CON(CH3)2
Aldehyde
Ketone
Carboxylic acid
Acid chloride
Ester
Amide
2.33
2.72
2.88
3.02
2.99
1.74
1.72
3.76
3.81

10. TYPES OF CARBONYL COMPOUNDS REACTIONS
GENERAL MECHANISMS
Nucleophilic addition
Nucleophilic acyl substitution
-Substitution
Condensation reactions

11. Nucleophilic addition to carbonyl group
1st step
Carbonyl carbon
rehybridizes
from sp2 to sp3

12. Nucleophilic addition to carbonyl group
2nd step
Two ways of stabilization
of tetrahedral intermediate

13. Nucleophilic addition to carbonyl group
EXAMPLE 1 – addition of methylmagnesium bromide to cyclohexanone
Synthesis of tertiary
alcohol from ketone

14. Nucleophilic addition to carbonyl group
EXAMPLE 2 – cyclohexanone imine formation
Net effect – replacing
C=O by C=NR

15. Nucleophilic acyl substitution
Net effect – replacing of group Y with nuclephile.
-Y is called leaving group
Y = -OR (ester)
-OCOR (anhydride)
-Cl (acid chloride)
-NH2, -NHR, -NR2 (amide)

16. Nucleophilic acyl substitution
EXAMPLE – ester synthesis from acid chloride and alkoxide
Net effect – replacing
of Cl by OR

17. -Substitution reactions -substituted carbonyl compound
Intermediates

18. -Substitution reactions
Net effect – extending of carbonyl compound hydrocarbon
framework by –CH2R fragment at -carbon

19. -Substitution reactions
EXAMPLE – -methylation of cyclohexanone

20. Carbonyl condensation reactions
New C-C bond
Two aldehydes
Aldol product
(aldehyde + alcohol)

21. Carbonyl condensation reactions
Carbonyl condensation reaction is a combination of -substitution step
and nucleophilic addition step
acetaldehyde
By condensation of acetaldehyde
3-hydroxybutanal is prepared
3-hydroxybutanal

22. Nucleophilic addition reactions of carbonyl compounds
Alcohol
Alcohol
Cyanohydrin
Alkene
Imine
Alkane
Acetal
Enamine

23. Negatively charged nucleophiles
Neutral nucleophiles
Hydroxide ion
Hydride ion
A carbanion
An alkoxide ion
Cyanide ion
Water
An alcohol
Ammonia
An amine