How are ketones prepared in the laboratory?

Laboratory Preparation of Ketones

1. From Secondary Alcohols
   Secondary alcohols are oxidized with suitable oxidizing agents. Unlike primary alcohols, they stop at the ketone stage and do not undergo further oxidation under normal conditions.
2. From Acyl Chlorides (Friedel–Crafts Acylation)
   Aromatic ketones can be prepared by treating an aromatic compound with an acyl chloride in the presence of a Lewis acid catalyst such as aluminium chloride.
3. From Nitriles
   Nitriles can be reacted with Grignard reagents, followed by hydrolysis, to give ketones.
4. From Carboxylic Acids
   Carboxylic acids are converted into ketones through the reaction with organometallic reagents (such as dialkylcadmium compounds).
5. From Esters
   Esters react with Grignard reagents, producing ketones after controlled reaction and hydrolysis.
6. From Alkenes (Ozonolysis)
   Alkenes undergo ozonolysis (reaction with ozone, followed by reduction), breaking the double bond and forming ketones (or aldehydes, depending on the structure).
7. From Alkynes
   Terminal alkynes undergo hydration in the presence of mercury(II) salts and strong acid to give methyl ketones (Markovnikov addition).

In short: Ketones are commonly prepared by oxidation of secondary alcohols, Friedel–Crafts acylation of aromatics, reactions of esters, nitriles, and acids with organometallic reagents, and by ozonolysis or hydration of unsaturated hydrocarbons.