Eco-friendly and one-pot synthesis of 1,8-dioxooctahydroxanthene derivatives catalyzed by task-specific Bronsted acidic ionic liquid

Efficient and one-pot synthesis of 1,8-dioxo-octahydroxanthenes was described by Knoevenagel condensation, Michael addition and cyclodehydration of dimedone. This reaction was carried out through condensation of dimedone and various aromatic aldehydes in the presence of task-specific Br?nsted acidic ionic liquid under solvent free conditions. The catalyst could be recycled five times without significant loss of its catalytic activity.