Brønsted acid ionic liquid catalyzed formation of pyruvaldehyde dimethylacetal from triose sugars

A series of sulfonic acid functionalized ionic liquids (SO₃H-ILs) have been synthesized, characterized and investigated as catalysts for the conversion of the triose sugars, 1,3-dihydroxyacetone (DHA) and glyceraldehyde (GLA), to pyruvaldehyde dimethylacetal (PADA) in methanol. Depending on the reaction conditions and the applied SO₃H-ILs a good yield of up to 52% of PADA was obtained. Under identical reaction conditions the derivative of PADA, 1,1,2,2-tetramethoxy propane (TMP), could be obtained in yields up to 49% using another SO₃H-IL.