Ketone

Reactions

Synthesis

Ketones can be created by oxidation of secondary alcohols. The process requires a strong oxidising agent such as potassium dichromate or other reagents containing Cr(VI). The alcohol is oxidised by heating under reflux in acidified solution. For example 2-propanol is oxidised to propanone (acetone):

Related Topics:
Oxidation - Alcohol - Oxidising - Potassium dichromate - Cr(VI) - Reflux - 2-propanol - Acetone

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:H3C-CH(OH)-CH3 → H3C-CO-CH3

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Two atoms of hydrogen are removed, leaving a single oxygen atom double bonded to a carbon atom.

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Ketones are also prepared by Gem halide hydrolysis. Aromatic ketones can be prepared in the Friedel-Crafts reaction and the Fries rearrangement.

Related Topics:
Gem halide hydrolysis - Friedel-Crafts reaction - Fries rearrangement

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Reactions

Nucleophilic addition

ketone + nucleophile → tetrahedral carbonyl addition compound

Related Topics:
Nucleophile - Tetrahedral carbonyl addition compound

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• ketone + anion of terminal alkyne → tetrahedral carbonyl addition compound (alkoxide)
• *alkoxide + aqueous acid → hydroxyalkyne
• ketone + ammonia or primary amine ↔ tetrahedral carbonyl addition compound
• *tetrahedral carbonyl addition compound + acid catalyst → imine + water
• ketone + secondary amine ↔ tetrahedral carbonyl addition compound
• *tetrahedral carbonyl addition compound + acid catalyst → enamine + water
• ketone + Grignard reagent → magnesium alkoxide
• *magnesium alkoxide + aqueous acid → tertiary alcohol
• ketone + organolithium reagent → lithium alkoxide
• *lithium alkoxide + aqueous acid → tertiary alcohol
• ketone + alcohol + acid or base ↔ hemiacetal + water
• *hemiacetal + alcohol + acid catalyst ↔ acetal + water
• *This is a carbonyl-protecting reaction.

Electrophilic addition

• ketone + electrophile → resonance stabilized cation

Wittig reaction

• *ketone + phosphonium ylide → oxaphosphetane
• **oxaphosphetane → phosphine oxide + alkene

Other

• ketone + water ↔ geminal diol
• ketone + thiol + acid catalyst ↔ thioacetal + water
• ketone + hydrazine or derivative of hydrazine → hydrazone
• ketone + metal hydride → metal alkoxide salt
• *metal alkoxide salt + water → alcohol
• ketone + → enolate

Keto-enol tautomerism

• ketone + acid catalyst ↔ enol
• *enol + halogen → α-haloketone

Reactions at an α-carbon

• ketone + aqueous deuterium + D⁺ or OD^- catalyst → ketone-d + HOD