1,8-Dioxo-octahydroxanthenes have been synthesized in good yields by reaction of arylaldehydes and dimedone in the presence of a catalytic amount of acetic acid, without use of any additional co-catalyst, under solvent-free, thermal conditions. We also report preparation of 1,8-dioxo-decahydroacridines by reaction of arylaldehydes, dimedone, and amines or ammonium acetate under solvent-free, thermal
Saccharose as a new, natural, and highly efficient catalyst for the one-pot synthesis of 4,5-dihydropyrano[3,2-c]chromenes, 2-amino-3-cyano-4H-chromenes, 1,8-dioxodecahydroacridine, and 2-substituted benzimidazole derivatives
Saccharose was applied as a green and natural catalyst for the one-pot, three-component condensation between aromatic aldehydes, malononitrile, and resorcinol, or 4-hydroxycoumarine to afford the corresponding pyran-annulated heterocyclic systems. This green methodology offers several advantages such as the use of a non-hazardous catalyst, easy access, clean work-up, excellent yields, short reaction time, and environmentally mild conditions. In addition, 1,8-dioxodecahydroacridine and 2-substituted benzimidazole derivatives have been synthesized from commercially available starting materials, arylaldehydes, dimedone, amines, or ammonium acetate and o-phenylenediamine using the mentioned catalyst.