AbstractHydroxyalkylation of phenol with glyoxylic acid, catalyzed by AlIII, results, under neutral aqueous conditions, inortho‐rich mixtures of hydroxymandelic acids.Para‐rich mixtures of hydroxymandelic acids are obtained by ZnIIcatalysis under slightly alkaline conditions. A new separation method of these mixtures into the pure alkali salts of 2‐ and 4‐hydroxymandelic acid is presented. Formation of a complex between the alkali ion and three co‐operating oxygen atoms of 2‐hydroxymandelate explains the excellent solubility of theorthoisomer in acetone, enabling extraction of this isomer selectively from mixtures of alkali salts of 2‐ and 4‐hydro