In the presence of diethyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate（DHP） and a catalytic amount of potassium iodide,severalα-halo ketones were easily reduced to the corresponding ketones in acetone media....In the presence of diethyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate（DHP） and a catalytic amount of potassium iodide,severalα-halo ketones were easily reduced to the corresponding ketones in acetone media.The procedure presented here showed several merits such as short reaction time,practical experimental and isolated procedure,and excellent yields of products.展开更多
A new series of compounds, 1-aryl-3-（3,4-dihydro-2H-chromen-5-yl） ureas, have been synthesized and their structures were confirmed by FAB-MS and IH NMR. The preliminary pharmacological screening showed that these co...A new series of compounds, 1-aryl-3-（3,4-dihydro-2H-chromen-5-yl） ureas, have been synthesized and their structures were confirmed by FAB-MS and IH NMR. The preliminary pharmacological screening showed that these compounds inhibited TNF-α production in lipopolysaccharide （LPS）-stimulated THP-1 cells.展开更多
A one pot reaction of 5-trifluoroacetyl-3,4-dihydro-2H-pryane with alkyl bromide RBr in the presence of zinc powder gave corresponding alcohol (CH2)3OCH=C(R)C(CF3)OH (R:CH2=CHCH2-, 3a; CH2CO2Me 3b), 3b are readily hyd...A one pot reaction of 5-trifluoroacetyl-3,4-dihydro-2H-pryane with alkyl bromide RBr in the presence of zinc powder gave corresponding alcohol (CH2)3OCH=C(R)C(CF3)OH (R:CH2=CHCH2-, 3a; CH2CO2Me 3b), 3b are readily hydrolysed to corresponding carboxylic acid under dilute acidic condition, intramolecular cycle addition of this acid afforded bicyclo lactone. Treatment of 5 with pyridine and POCl3 to afford product dehydroration by the trifluoromethyl substituted α,β-unsaturated carbonyl compound 6.4- Trifluoroacetyl 2,3-dihydro-2H-furan behaves similar compounds 8, 9 and 10 are prepared.展开更多
A promising catalytic material, modified ga mma alumina with high surface area (300m2/g) and higher c ontents of strong acid sites was developed. It was prepared by a special precip itation method with aluminum nitra...A promising catalytic material, modified ga mma alumina with high surface area (300m2/g) and higher c ontents of strong acid sites was developed. It was prepared by a special precip itation method with aluminum nitrate solution containing a certain amounts of or thosilicic acid and ammonia aqueous solution. Compared with commercial gamma alu mina, the modified gamma alumina is an effective catalyst for dehydration of tet rahydrofurfuryl alcohol to 3,4-Dihydro-2H-pyran.Under the optimized reaction conditions, an improved yield of 3,4-Dihydro-2H-pyran of 93.4% was achieved. The profiles of pyridine TPD show that the modified gamma alumina exhibits more strong acid sites than that in the commercial gamma alumina, indicating the stro ng acid sites on the surface of the catalyst may play a crucial role in this rea ction.展开更多
基金the Guangdong Natural Science Foundation(No.8151063201000016)the National Natural Science Foundation of China(No.20672046) for financial support
文摘In the presence of diethyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate（DHP） and a catalytic amount of potassium iodide,severalα-halo ketones were easily reduced to the corresponding ketones in acetone media.The procedure presented here showed several merits such as short reaction time,practical experimental and isolated procedure,and excellent yields of products.
文摘A new series of compounds, 1-aryl-3-（3,4-dihydro-2H-chromen-5-yl） ureas, have been synthesized and their structures were confirmed by FAB-MS and IH NMR. The preliminary pharmacological screening showed that these compounds inhibited TNF-α production in lipopolysaccharide （LPS）-stimulated THP-1 cells.
基金The authors thank the National Natural ScienceFoundation of China (NNSFC)! (No. 29872051 and No. 29672041 )for financial support
文摘A one pot reaction of 5-trifluoroacetyl-3,4-dihydro-2H-pryane with alkyl bromide RBr in the presence of zinc powder gave corresponding alcohol (CH2)3OCH=C(R)C(CF3)OH (R:CH2=CHCH2-, 3a; CH2CO2Me 3b), 3b are readily hydrolysed to corresponding carboxylic acid under dilute acidic condition, intramolecular cycle addition of this acid afforded bicyclo lactone. Treatment of 5 with pyridine and POCl3 to afford product dehydroration by the trifluoromethyl substituted α,β-unsaturated carbonyl compound 6.4- Trifluoroacetyl 2,3-dihydro-2H-furan behaves similar compounds 8, 9 and 10 are prepared.
文摘A promising catalytic material, modified ga mma alumina with high surface area (300m2/g) and higher c ontents of strong acid sites was developed. It was prepared by a special precip itation method with aluminum nitrate solution containing a certain amounts of or thosilicic acid and ammonia aqueous solution. Compared with commercial gamma alu mina, the modified gamma alumina is an effective catalyst for dehydration of tet rahydrofurfuryl alcohol to 3,4-Dihydro-2H-pyran.Under the optimized reaction conditions, an improved yield of 3,4-Dihydro-2H-pyran of 93.4% was achieved. The profiles of pyridine TPD show that the modified gamma alumina exhibits more strong acid sites than that in the commercial gamma alumina, indicating the stro ng acid sites on the surface of the catalyst may play a crucial role in this rea ction.
