In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups.

1. Aldehydes and Ketone
Subject Expert
Dr. Tanuja Nautiyal
Sharda Public School, Almora
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2. Carbonyl compounds
Aldehydes
Acid chlorides
Amides
Ketones
Carboxylic acid
Esters
-al
----
-amide
-formyl
-halo
-amino
-one
-oic acid
-oate
-oxo
-carboxy
-alkoxycarbonyl
Carbonyl compounds Suffix name prefix name
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3.  Aldehydes and Ketones both have a carbon-oxygen double
bond called as carbonyl group.
 Both aldehyde and ketones possess the same general formula
Cn(H2O)n.
Aldehydes and Ketones
C H C C
Aldehyde Ketone
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4.  The carbon-oxygen double bond is different than carbon-
carbon double bond. Since, oxygen is more electronegative,
the electrons of the bond are attracted towards oxygen. CO
bond is shorter, stronger and more polar than C=C bond in
alkenes. Consequently, oxygen attains a partial negative
charge and carbon a partial positive charge making the
bond polar, it is proposed that carbonyl group is a resonance
hybrid.
Structure of Carbonyl carbon group
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5.  Carbonyl carbon atom is joined to three atoms by sigma
bonds. Since these bonds utilize sp2 -orbitals, they lie in
the same plane and are 120° apart.
Structure of Carbonyl carbon group
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6. Difference between of Carbonyl carbon C=O bond
and alkene carbon C=C bond
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7. Boiling Points
 Aldehydes and ketones are more polar, so they have a higher
boiling point than comparable alkanes or ethers.
 Aldehydes and ketones can not make hydrogen bond with
each other, so their boiling point is lower than comparable
alcohol.
1- Propanol Boiling point: 970C
Methoxyethane Boiling point: 80C
Propanal Boiling point: 490C
Acetone Boiling point: 560C
Butane Boiling point: 00C
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8. Solubility of Aldehydes and Ketones
Aldehydes and ketones are good solvent for alcohols.
The lone pair of electrons on oxygen of carbonyl can
accept a hydrogen bond from O-H.
Acetaldehyde and Acetone are soluble in water
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9.  Aldehyde has a greater partial positive charge on its
carbonyl carbon than ketone
Relative reactivity of Aldehydes and Ketones
Increasing reactivity
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10.  The carbonyl carbon of an aldehyde is more accessible to
the nucleophile. Ketones have steric hindrance than
aldehydes, greater steric hindrance is responsible for its
less stability.
Relative reactivity of Ketones
Increasing reactivity
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11. Nomenclature of Aldehydes and Ketones
 The aldehyde carbon is 10 carbon. In nomenclature –e
is replaced with –al.
 In nomenclature of ketone –e is replaced with –one.
 In cyclic ketone carbonyl group is assigned the no. 1
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12. Common names
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13. Nomenclature of Aldehydes and Ketones
3-methyl-pentanal-1 3-methyl -2- butanone
3-bromo-cyclohexanone
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14. Preparation of Aldehydes and Ketones
A. Oxidation of Alcohols
B. Oxidation of Alkylbenzene
C. Reduction of Carboxylic acid
D. Reduction of Acid Chlorides(Friedel Crafts Reaction)
E. By using Grignard Reagent
F. Hydration of Alkynes
G. Hydroboration-Oxidation of Alkenes
H. Ozonolysis of Alkenes
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15. 10 alcohol Aldehyde
n- Butyl alcohol Butanal
Oxidation of alcohol
20 alcohol
Ketone
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16. Oxidation of primary alcohols to ketone, pyridinium
chlorochromate (PCC) is used as an oxidising agent
Oxidation of alcohols
Oxidation of secondary alcohols by sodium dichromate in
sulphuric acid or by potassium permanganate give ketone.
Cyclohexylmethanol Cyclohexanecarbaldehyde
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17. Oxidation of alkyl-benzene
Alkyl benzene Aldehyde
p- Bromotoluene p- Bromobenzaldehyde
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18. Reduction of carboxylic acid by using Lithium Aluminium
Hydride (LiAlH4) gives aldehydes or ketones.
Carboxylic
acid
Aldehyde
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19. Reduction of acid chlorides
Acid chlorides Aldehyde
p- Nitrobenzoyl chloride p- Nitrobenzaldehyde
Lithium aluminium tri (t-butoxy) hydride is a milder reducing
agent that reacts faster with acid chlorides than with
aldehydes
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20. Lithium dialkylcuprate (Gilman reagent) transfer one of its
alkyl group in acid chloride.
Lithium
dialkylcuprate
Acid chloride Ketone
Reduction of Acid chloride
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21. Reaction between an acyl halide and an aromatic ring will
produce a ketone
Friedel- Crafts Reaction
Benzophenone
Acid chloride Ketone
Benzoyl chloride
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22. Preparation of ketone from Grignard reagent
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23. Hydration of Alkynes
Hydration of alkynes gives aldehydes or ketones, the initial
product is an enol, which quickly tautomerizes to its keto
form.
Alkynes Enol Methyl ketone
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24. Hydroboration- Oxidation of Alkynes
Hydroboration- oxidation of an alkyne gives aldehyde,
anti- markovnikov addition of water across the triple
bond.
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25. Ozonolysis of Alkenes
In ozonolysis, the double bond in alkene is cleaved by ozone,
followed by reduction, and the products are aldehydes or
ketones.
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26. SHARDA PUBLIC SCHOOL, ALMORA

27. If the nucleophile that adds to the aldehyde or ketone is an
Oxygen or Nitrogen, a nucleophilic-elimination reaction will
occur.
Nucleophilic addition reaction: Aldehydes and ketones react
with nucleophiles to form addition products.
Chemical properties of Aldehydes and Ketones
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28. Reduction of Aldehydes or ketones
Addition of hydride ion to an aldehyde or ketone forms
and alkoxide ion, then protonation by an acid produces
an alcohol.
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29. Aldehydes or
ketones
Alcohol
Aldehydes or
ketones
Alcohol
H2+Ni, Pt or Pd
Reduction of aldehydes or ketones
LiAlH4 or NaBH4
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30. Reduction of Aldehydes and Ketones
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31. Reduction of aldehydes and ketones
Aldehydes or
ketones
Alkanes
Aldehydes or
ketones
Alkanes
Zn(Hg), conc.HCl
NH2NH2, base
Clemmensen reduction
Wolff-Kishner reduction
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32. The Wolff-Kishner reduction
When a ketone or an aldehyde in a basic solution of hydrazine,
the carbonyl group is converted into a methylene group.
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33. Mechanism
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34. Mechanism of reduction of Carboxylic acid with LiAlH4
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35. Oxidation of aldehydes and ketones
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36. Tollen’s test (Silver mirror test)
Colourless
solution
Silver- mirror
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37. Haloform reaction
Oxidation of methyl ketone
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38. Mechanism of Haloform reaction:
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39. Reaction with Grignard reagent
Grignard reagents react with aldehydes, ketones and carboxylic
acid derivatives
Propanal Grignard reagent
3-hexanol
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40. Examples: Reaction with Grignard reagent
Butanal 1-phenyl-1-butanol
3-pentanone
3-methyl 3-pentanol
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41. The Witting Reaction
A phosphorus ylide is used as the nucleophile in the
reaction. In this reaction, conversion of carbonyl group into a
new C=C double bond occurs.
Phosphorus ylide Trimethylphosphine
oxide
ketone Alkene
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42. Triphenylphosphine oxide
Ylide Aldehyde or
ketone
Betaine Oxaphosphetane
Oxaphosphetane Alkene
+
Mechanism of Witting reaction
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43. Reaction with Acetylide ions
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44. Reaction with Acetylide ions
Acetylide ions
Acetylide ions Alcohol
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45. Reaction with Hydrogen Cyanide
Acetone Acetone
cyanohydrin
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46. Reaction with Hydrogen Cyanide
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47. Reactions of Aldehydes and Ketones with Nitrogen nucleophile
Aldehydes and Ketones react with amines to form imine and
enamine.
Aldehyde or Ketone Primary amine Imine
Aldehyde or Ketone Secondary amine enamine
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48. Reactions of Aldehydes and Ketones with Nitrogen nucleophile
Benzaldehyde ethylamine Imine
Cyclopentanone diethylamine
enamine
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49. Mechanism
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50. Mechanism
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51. Aldehyde or ketone + Hydroxylamine Oxime
Aldehyde or ketone + Hydrazine Hydrazone
Aldehyde or ketone + phenylhydrazine Phenylhydrazone
Aldehyde or ketone + Semicarbazone Semicarbazone
Addition of derivatives of ammonia
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52. Addition of derivatives of ammonia
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53. Aldehyde
ketone
ketone
Hydroxylamine Oxime
Hydrazine Hydrazone
SemicarbazoneSemicarbazide
Reactions of Aldehydes and Ketones with Nitrogen nucleophile
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54. Reactions of Aldehydes and Ketones with Nitrogen nucleophile
Hydrazine Hydrazone
SemicarbazoneSemicarbazide
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55. Addition of water
Addition of water molecule to an aldehyde or a ketone form
a hydrate (gem-diols), are unstable.
aldehyde
or ketone
water hydrate (gem-diols),
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56. Addition of alcohol
Addition of an alcohol and a ketone produce hemiketal,
after the addition of another alcohol produce ketal.
ketone
hemiketal ketal
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57. Addition of alcohol
Addition of an alcohol and an aldehyde produce hemiacetal,
after the addition of another alcohol produce acetal.
an aldehyde hemiacetal acetal
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58. Cannizzaro rection
Addition of two aldehydes (with no a- hydrogen) in presence
of strong base give one alcohol and one acid salt.
Aldehyde
(no a-Hydrogen)
Acid salt Alcohol
Formaldehydes
(no a-Hydrogen)
Formate ion Methanol
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59. Mechanism of Cannizzaro reaction
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60. Halogenation of aldehydes or ketones
When Cl2, Br2 or I2 is added to the acidic solution of an aldehyde
or a ketone, a halgoen replaces one of the a- hydrogens of the
carbonyl compound.
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61. The carbon adjacent to a carbonyl carbon is called an a- carbon,
the hydrogen bonded to a-carbon is called a-Hydrogen. The a-
hydrogen bonded to a carbon adjacent to a carbonyl carbon is
sufficiently acidic to be removed by a strong base.
An a- hydrogen is more acidic than hydrogen bonded to other
sp3 hybridized carbon, because the base formed when a proton
is removed from other sp3 hybridized carbons, the acid strength
is determined by the stability of the conjugate base that is
formed when the acid gives up a proton.
Acidity of a-hydrogen
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62. Acidity of a-hydrogen
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63. Halogenation of a-Carbon
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64. 2-methylcyclohexanone
2-6 dimethylcyclohexanone 2-2 dimethylcyclohexanone
Mechanism of halogenation of a-Carbon
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65. Aldol condensation
Addition of two molecules of aldehydes or two molecules of
ketones (contain a-hydrogen) form aldol (“ald”for aldehyde
and “ol” for alcohol)
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66. Mechanism of Aldol condensation
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67. When two different carbonyl compounds are used in an aldol
condensation, four products are formed, these products have
similar physical properties.
Mixed Aldol or Crossed Aldol Condensation
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