Collect. Czech. Chem. Commun. 1985, 50, 2252-2259

Kinetics and mechanism of base-catalysed aldolization of 1,3-dimethoxy-2-propanone

Michal Fedoroňko, Mária Petrušová and Vladimír Kováčik

Chemical Institute, Chemical Research Center, Slovak Academy of Sciences, 842 38 Bratislava


1,3-Dimethoxy-2-propanone (HA) in an aqueous alkaline solution undergoes specifically base-catalysed aldolization with the formation of a dimer, 4-hydroxy-1,3,5-trimethoxy-4-methoxymethyl-2-pentanone (H2A2). The reaction is reversible and involves the formation or decomposition of an intermediate anion, HA2-, as the rate-determining step. The formation of a carbanion ion, A-, of the starting compound and of the HA2- anion are rapid, preceding, and generally base-catalysed reaction steps. The activation and thermodynamic parameters of the reversible reaction were determined from the dependences of the rate and equilibrium constants on the temperature.