Acyloin

Acyloins (also referred to as ketols, or alpha-hydroxy ketones) are a class of organic compounds in organic chemistry sharing a common functional group consisting of a hydroxyl group placed on the α-position of a carbonyl group.

Quotes

 * Many oxidants transform acyloins (α-hydroxy ketones) into α-diketones. Copper and bismuth oxidants are commonly selected for this transformation. … Cu(II) salts (e.g., Cu(OAc), or CuSO4) in stoichiometric amounts convert acyloins into diketones. Catalytic amounts of cupric acetate can be used in conjunction with ammonium nitrate. … Commercially available Bi2O3, in the presence of acetic acid, oxidizes acyloins to α-diketones in good yields.
 * George S. Zweifel and Michael H. Nantz, Modern Organic Synthesis (2006), Ch. 4 : Functional Group Transformations: Oxidation and Reduction