The acidity of a proton (hydrogen) alpha to most carbonyl compounds is around pKa = 25, but drops to what with two carbonyls attached to the same sp3 carbon with a hydrogen?

MCQS on the nomenclature, properties, and reactivity of ethers and epoxides, thiols and sulfides, conjugated dienes, benzene and other aromatic compounds, amines, aldehydes and ketones, carboxylic acids, carboxylic acid derivatives, and enols and enolates.