Abstract
A facile and efficient procedure has been developed by one-pot condensation of β-naphthol, aldehydes, and cyclic 1,3-dicarbonyl compounds for the synthesis of 8,9,10,12-tetrahydrobenzo[a]xanthen-11-one or 8,9-dihydrobenzo-[f]cyclopenta[b]chromen-10(11H)-one derivatives catalyzed by p-toluenesulfonic acid under solvent-free and sonication conditions.
ACKNOWLEDGMENT
We are grateful to the Science and Technology Projects of Zhejiang (Nos. 2008C11046 and 2007C21111) for financial support.
Notes
a Reaction conditions: benzaldehyde 1a (1 mmol), β-naphthol 2 (1 mmol), 5,5-dimethyl-cyclohexane-1,3-dione 3 (1.2 mmol), p-TSA (0.1 mmol), solvent (3 mL), 70°C.
b Isolated yield.
c The reaction was carried out by stirring instead of sonic irradiation.
a Reaction conditions: aldehyde 1 (1 mmol), β-naphthol 2 (1 mmol), 5,5-dimethyl-cyclohexane-1,3-dione 3 (1.2 mmol), p-TSA (0.1 mmol), 70°C.
b Isolated yield.
c Cyclopentane-1,3-dione was substituted for 5,5-dimethyl-cyclohexane-1,3-dione 3.
a Reaction conditions: aldehyde 1 (1 mmol), β-naphthol 2 (1 mmol), cyclopentane-1,3-dione 5 (1.2 mmol), p-TSA (0.1 mmol), 70°C.
b Isolated yield.