Which oxidation method fully oxidizes primary alcohols to carboxylic acids?

• A. Dess-Martin periodinane
• B. Swern oxidation
• C. PCC
• D. Jones oxidation

Answer: (D)

To push a primary alcohol all the way to a carboxylic acid you need a strong oxidant under conditions that keep oxidizing beyond the aldehyde. Jones oxidation uses chromium(VI) in acidic aqueous solution (chromic acid in sulfuric acid with acetone). Those harsh, strongly oxidative conditions quickly convert the alcohol first to an aldehyde and then, in the same reaction mixture, the aldehyde is further oxidized to the carboxylic acid. In contrast, the milder oxidants used in the other methods—Dess-Martin periodinane, Swern oxidation, and PCC—are designed to stop at the aldehyde, so they don’t normally give the carboxylic acid from a primary alcohol. So the method that fully oxidizes primary alcohols to carboxylic acids is Jones oxidation.