In organic chemistry, acyloins or α-hydroxy ketones[1] are a class of organic compounds of the general form R−C(=O)−CR'(OH)−R", composed of a hydroxy group (−OH) adjacent to a ketone group (>C=O). The name acyloin is derived from the fact that they are formally derived from reductive coupling of carboxylic acyl groups (R−C(=O)−).[1] They are one of the two main classes of hydroxy ketones, distinguished by the position of the hydroxy group relative to the ketone; in this form, the hydroxy is on the alpha carbon, explaining the secondary name of α-hydroxy ketone.