Ketones can be synthesized using several methods, including:
Oxidation of secondary alcohols, where a secondary alcohol is treated with an oxidizing agent such as chromic acid or pyridinium chlorochromate (PCC).
Friedel-Crafts acylation, in which an aromatic compound reacts with an acyl chloride in the presence of a Lewis acid catalyst like aluminum chloride to form an aromatic ketone.
Ozonolysis of alkenes, where the carbon-carbon double bond of an alkene is cleaved using ozone, followed by reductive workup.