©2017 National Information and Documentation Center (NIDOC) E CO-FRIENDLY one pot synthesis is developed for 1,8-dioxo-octahydroxanthenes from aldehydes and dimedone using non-toxic, easily prepared and recyclable catalyst (Sm 2 O 3 / SiO 2 ) as a silica supported rare earth element under solvent-free conditions.four of the synthesized compounds showed promising ABTS (3i, 68.7; 3b, 59.2; 3h, 50.2 ...