ChemInform Abstract: Domino Knoevenagel/Michael Synthesis of 2,2′-Arylmethylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one) Derivatives Catalyzed by Silica-Diphenic Acid and Their Single Crystal X-Ray Analysis

An efficient and eco-friendly procedure has been developed for the synthesis of various 2,2’-arylmethylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) derivatives which were isolated and characterized by melting point, IR, 1H-NMR, 13C-NMR and mass spectrometric techniques. Out of the fourteen compounds synthesized, four compounds yielded crystals suitable for single crystal X-ray analysis which showed that 2,2’-phenylmethylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) crystallizes in the tetragonal system with space group I 4 1 /a, 2,2’-(3-nitrophenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) crystallizes in the monoclinic system with space group P 2 1 /n, 2,2’-(4-nitrophenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) crystallizes in the orthorhombic system with space group Pca21 and 2,2’-(4-chlorophenyl)methylenebis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) crystallizes in the monoclinic space group P21/c.