Abstract
An efficient synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one derivatives via the three-component condensation of aromatic aldehyde, 2-naphthol, and 5,5-dimethyl-1,3-cyclohexanedione was carried out in 76–93% yields at 40–42 °C using p-dodecylbenzenesulfonic acid as catalyst in aqueous media under ultrasound irradiation.
GRAPHICAL ABSTRACT
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ACKNOWLEDGMENT
We thank the Natural Science Foundation of Hebei Province (B2006000969), China, for financial support.
Notes
a Substrate: benzaldehyde, 1 mmol; 2-naphthol, 1 mmol; 5,5-dimethyl-1,3-cyclohexanedione, 1.2 mmol; water 2 mL.
b Stirring alone without ultrasound.
c Solvent-free.
d Ethanol as solvent. The product is 3-ethoxy-5,5-dimethylcyclohex-2-enone.
e Methanol as solvent. The product is 3-methoxy-5,5-dimethylcyclohex-2-enone.
a Substrate: aryl aldehyde, 1 mmol; 2-naphthol, 1 mmol; 5,5-dimethyl-1,3-cyclohexanedione, 1.2 mmol; DBSA, 0.1 mmol; H2O, 2 mL.
b Stirring alone without ultrasound.
a Condensation of benzaldehyde, 2-naphthol, and 5,5-dimethyl-1,3-cyclohexanedione.
b Condensation of benzaldehyde, 1-naphthol, and 5,5-dimethyl-1,3-cyclohexanedione.