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Organic ChemistryKetones and Aldehydes

Diah Agustina Puspitasari, ST., MT

Chemical Engineering Department

Engineering Faculty of Brawijaya University

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Carbonyl Compounds

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Structure of The Carbonyl Group

Carbon is sp2 hybridized.

C=O bond is shorter, stronger, and

more polar than C=C bond in alkenes.

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IUPAC Names forKetones

Replace -ewith -one.

Indicate the position of the carbonyl witha number.

Number the chain so that carbonyl carbonhas the lowest number.

For cyclic ketones the carbonyl carbon is

assigned the number 1.

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Examples

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Naming Aldehydes

Systematic names for aldehydes are derived byreplacing the final e af the alkane with al.

An aldehydes carbon is at the end of a chain, soit number 1.

If the aldehydes group is attached to a largeunit (usually a ring), the suffix carbaldehyde isused.

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Examples

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Common Names of Aldehydes

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Boiling Points

More polar, so higher boiling point thancomparable alkane or ether.

Ketone and aldehydes have no O-H bond so theirmolecules cant form hydrogen bonds with eachother.

The boiling points are lower than alcohol

Chapter 18 9

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Solubility

Good solvent for alcohols. Lone pair of electrons on oxygen of

carbonyl can accept a hydrogen bond

from O-H or N-H. Acetone and acetaldehyde are misible in

water.

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PhysicalPropertiesof Ketones and Aldehydes

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Formaldehyde

Gas at room temperature.

Formalin is a 40% aqueous solution.

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Industrial Importance

Solvents.

Polymers like Bakelite, phenol-formaldehydes resins, urea-formaldehydes glues, etc.

as a starting material in themanufcature of acetic acid, polymer and

drug. Flavorings and additives like vanilla,

cinnamon, artificial butter.

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Ketone and aldehydes inHouse Hold Product

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Syntheses of Ketoneand Aldehydes

Oxidation alcohols.

Ozonolysis of alkenes.

Syntheses of ketone using organolithium

reagents with carboxylic. Aldehyde syntheses by reduction of acid

chlorides.

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A. Oxidation Alcohols

Secondary alcohols ketones

Primary alcohols aldehydes

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B. Ozonolysis of alkenes

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C. Syntheses of ketone usingorganolithium reagents with

carboxylic.

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D Ald h d h b d i f

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D. Aldehyde syntheses by reduction ofacid chlorides.

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Reaction of Ketones andAldehydes

Addition of organometalic reagent.

Reduction reaction.

Hydration.

Oxidation of aldehydes.

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dd f l

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a. Addition of organometalicreagent

Addition to Aldehydes:

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Addition to Aldehydes:Formation of Secondary

Alcohols

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Addi i K

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Addition to Ketones:Formation of Tertiary

Alcohols

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b. Reduction Reaction

Ketones and aldehydes are most commonlyreduced by sodium borohydride.

NaBH4 reduced ketone to secondary alcohols

and aldehydes to primary alcohol

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In an aqueous solution, a ketone or analdehyde is in equilibrium with its hydrate, ageminal diol.

Hydration occurs through the nucleophilicaddition mechanism, with water (in acid) or

hydroxide ion (in base) serving as thenucleophile.

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c. Hydration

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Hydration of ketones and aldehydes

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d. Oxidation ofaldehydes