1. Aldehydes and Ketones

2. Structure

3. Structure

4. Nomenclature of aldehydes
Aldehydes are named by adding the suffix -al to the name of the corresponding hydrocarbon. The carbonyl carbon is given the number 1.
ethanal acetaldehyde

5. Nomenclature of aldehydes

6. Nomenclature of aldehydes
When -CHO is attached to a ring, the suffix carbaldehyde is used.
benzenecarbaldehyde
benzaldehyde
3-methylpentanal

7. Nomenclature of aldehydes

8. Nomenclature of ketones
Ketones are named using the name of the corresponding hydrocarbon followed by the suffix -one. The position of the carbonyl carbon must be indicated.
propanone
acetone
dimethyl ketone
One can also name the two radicals, R and R’, followed by the word ketone.

9. Nomenclature of ketones
ethyl methyl ketone
1-phenyl-2-propanone benzyl methyl ketone

10. Nomenclature of ketones
diphenylmethanone
benzophenone
phenylethanone
acetophenone

11. Nomenclature of ketones

12. Synthesis of aldehydes - oxidation of primary alcohols
PCC = pyridinium chlorochromate

13. Rosemund reduction RCHO or ArCHO
A special catalyst is used: palladium on barium sulfate which has been deactivated (poisoned) with an amine such as quinoline.

14. Lithium tri-tert-butoxyaluminium hydride
See page 692 or 722 for the mechanism (we’ll look
at this later).

15. Synthesis of ketones - oxidation of secondary alcohols

16. Synthesis of ketones - oxidation of secondary alcohols

17. Synthesis of ketones – hydration of alkynes

18. Keto - enol tautomerism
Structural isomers that are formally related only by the shift of a hydrogen and one or more  bonds are called tautomers.

19. Friedel-Crafts acylation

20. Reaction of acid chlorides with dialkylcuprates

21. Oxidation of aldehydes
RCO2H or ArCO2H

22. Tollens’ test
colorless solution
silver mirror

23. Oxidation of ketones - the haloform reaction

24. Reactivity of the carbonyl group

25. Nucleophilic addition

26. Nucleophilic addition - acid catalysis

27. Addition of cyanide
cyanohydrin

28. Addition of cyanide

29. Addition of Grignard reagents

30. Reduction to alcohols

31. Reduction to alcohols

32. Reduction to alcohols
hydride transfer

33. Addition of ammonia derivatives

34. Addition of ammonia derivatives
free base
salt H + C N G
N-G + H
O + H+ 2 OH

35. Addition of ammonia derivatives

36. Addition of ammonia derivatives

37. Reduction to hydrocarbons
Zn(Hg), conc. HCl
Clemmensen reduction
Wolff-Kishner reduction

38. Reduction to hydrocarbons
an antiseptic

39. Addition of alcohols

40. Addition of alcohols - hemiacetal formation

41. Acetal formation

42. Reactions of acetals H + H 'R C OR
+ H O
2ROH + R'-C=O 2 OR H

43. Acetals as protecting groups

44. Wittig reaction + (C6H5)3PO triphenylphosphine an ylid oxide
Georg Wittig, University of Heidelberg, Nobel Prize 1979

45. Wittig reaction - ylid formation
alkyltriphenylphosphonium halide
triphenylphosphine
an ylid

46. Wittig reaction

47. Cannizzaro reaction

48. Cannizzaro reaction

49. Mechanism

50. Analysis of aldehydes and ketones
They react with 2,4-dinitrophenylhydrazine.
Aldehydes give a positive Tollens’ test.
Methyl ketones give a positive iodoform test.

51. Spectroscopic propertiesIR
cm-1 - C=O stretching
~2720 cm-1 - C-H stretching in aldehydes
NMR
chemical shift of aldehyde proton:  =

52. Problems
Try problems 16.23, 16.24, 16.26, 16.28, 16.31, 16.35, 16.37, and