Theoretical study of Al(III)-catalyzed conversion of glyoxal to glycolic acid: dual activated 1,2-hydride shift mechanism by protonated Al(OH)3 species.

Density functional theory calculations demonstrate that Al(III)-catalyzed conversion of glyoxal to glycolic acid proceeds via a 7-membered dual Lewis acid-hydrogen bonding activation transition state of the 1,2-hydride shift, rather than the previously proposed 5-membered metal-alkoxide chelate activation transition state.