-kˌtōn noun
( -s )
Etymology: reduct ion + -one
: any of a class of reducing enediol aldehydes or ketones RC(OH) . C(OH)COR ; especially : a crystalline osone HOCH 2 COCHO or a tautomer [as HOCH = C(OH)CHO] that is a strong reducing agent in alkaline solution and is obtained from glucose by alkaline degradation or from dihydroxy-acetone by oxidation; hydroxy-pyruvaldehyde
ascorbic acids … may be considered as reductones — W.W.Pigman & R.M.Goepp †1946