Eco-friendly one-pot synthesis of acetals and ketals by heterogeneously catalyzed liquid-solid phase reaction

Twelve classes of acetals and ketals were synthesized from aldehyde/ketone and glycol using TiSiW12O4/TiO2 as a novel eco-friendly catalyst. The physical characterizations were carried out by TG/DTA, FT-IR, XRD, and 1H NMR spectra. The results indicated that the catalyst showed excellent catalytic activity for the condensation reactions. The yield of 12 classes of acetals and ketals reached 56.3%-96.3% under the typical reaction conditions (the molar ratio of aldehyde/ketone and glycol was 1:1.5, the quantity of catalyst was 0.5% of feed stock, the reaction time was 1.0 h, and the reaction temperature was 80-116°C). The catalyst was easily recovered and reused to give almost the same yield of the product as that given by fresh TiSiW12O40/TiO2.