3. Aluminium dodecyl sulfate trihydrate [Al(DS)3].3H2O: An efficient Lewis acid-surfactant-combined catalyst for synthesis of 1,8-dioxo-octahydroxanthens and 1,8-dioxo-decahydroacridines

An efficient synthesis of 1, 8-dioxo-octahydroxanthens and 1, 8-dioxo-decahydroacridines from the reaction of 5,5-dimethyl-1,3-cyclohexanedione (dimedone) with aromatic aldehydes bearing electron-donating or withdrawing substituents either in the presence or absence of primary amines has been described in a single pot using a catalytic amounts of aluminum tris (dodecyl sulfate) trihydrate [Al(DS)3·3H2O] as a Lewis acid-surfactant-combined catalyst. Both reactions occurred at 80 oC. 1, 8-dioxo-octahydroxanthens has been synthesized under solvent-free conditions and water is used as a green solvent for the synthesis of 1, 8-dioxo-decahydroacridines. This methodology offers several advantages such as very simple work-up procedure, short reaction times, and mild reaction conditions.