Oxidation of Alcohols

Alcohols can be oxidized, where the result depends on the structure of the alcohol. Tertiary alcohols can't be oxidized (there is no free C-H bond that can be oxidized to a C=O bond). Secondary alcohols are always oxidized to ketones and primary alcohols can be oxidized to aldehydes or carboxylic acids, depending of the strength of the oxidizing agent and the solvents present.

RCH₂OH + H₂CrO₄ → [ RCOH ] → RCOOH

Oxidizing agents like chromic acid are very reactive and will not stop after the oxidation of a primary alcohol to an aldehyde and will therefore create a carboxylic acid. Gentler oxidizing agents like pyridine chlorochromate (PCC) or hypochlorous acid will not continue after the aldehyde is formed. Note that this must happen in an anhydrous environment and that hypochlorous acid is very unstable and therefore needs to be created in the reaction mixture (for example using NaOCl in CH₃COOH). A big advantage of hypochlorous acid is that it is much less toxic than the other oxidizing agents.

H⁺

⟶