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Abstract

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.