Ultrasound-assisted synthesis of 1,8-dioxo-octahydroxanthene derivatives catalyzed by p-dodecylbenzenesulfonic acid in aqueous media

An efficient and convenient approach to the synthesis of 3,3,6,6-tetramethyl-9-aryl-1,8-dioxo-octahydroxanthene derivatives using p-dodecylbenzenesulfonic acid (DBSA) as the catalyst (10 mol.%) under ultrasound irradiation is described. This method provides several advantages such as environment friendliness, high yields and simple work-up procedure. In addition, water was chosen as a green solvent.     

一种快速高效分解1,1-二乙酸酯的方法

研究了硅胶硫酸酯催化下1,1-二乙酸酯的分解反应. 该方法具有操作简单、反应时间短、收率高、无污染、催化剂可回收重复使用等特点.     

铝-碱金属氟化物在超声辐射下于水中诱发的芳香醛还原偶联

超声辐射下, 铝粉在氟化钾或氟化钠的水溶液中, 可使芳香醛快速还原或偶联, 生成相应的双分子还原偶联产物和少量单分子还原产物, 其中还原偶联产物邻二醇的收率达15%～82%.     

One-Pot Synthesis of Tetrahydrobenzo-[b]-pyran Derivatives in Aqueous Media

In modem organic chemical research, 4H-benzo-[b]-pyran and their derivatives have attracted strong interest due to their useful biological and pharmacological properties. Herein, we report a clean one-pot synthesis of 2-amino-3-cyano-4-aryl-7,7-dimethyl-5-oxo-4H-5,6,7,8-tetrahydro-benzo-[b]-pyrans from aromatic aldehyde, malononitrile and 5,5-dimethyl-1,3-cyclohexadione using hexadecyl trimethyl ammonium bromide (HTMAB) as the catalyst. This method provides several advantages such as high yield, simple work-up procedure and environmental friendliness. All the products were characterized by 1H NMR and IR analyses.     

Ozone Oxidation of Oximes to Carbonyl Compounds

An efficient and convenient conversion of oximes to corresponding carbonyl compounds with ozone is reported.     

Montmorillonite Clay Catalysis XI1: Protection and Deprotection of Hydroxyl Group by Formation and Cleavage of Trimethylsilyl Ethers Catalysed by Montmorillonite K-10

An easy preparation of trimethylsilyl ethers of alcohols and phenols with 1,1,1,3,3,3-hexamethyldisilazane(HMDS) catalysed by montmorillonite K-10 at room temperature has been carried out in excellent yields. Desilyation of trimethylsilyl ethers is catalysed by K-10 in methanol at ambient temperature in high yields.     

Synthesis of 15-hydroxy-15(14→8)abeo-5α,(8S)-cholestane-3,14-dione

The synthesis of 15α-hydroxy-15(14→8)abeo-5α,(8S)-cholestane-3,14-dione (1) fromcholesterol in ten steps was described.The key step is the intramolecular aldol condensationof 3,14-dioxo-14,15-seco-5α-cholestan-15-al (3).     

水中"一锅法"合成2-氨基-3-氰基-4-芳基-7,7-二甲基-5-氧代-4H-5,6,7,8-四氢苯并[b]吡喃

报道了以十二烷基苯磺酸(DBSA)为催化剂,芳醛、丙二腈和5,5-二甲基-1,3-环己二酮为原料于水中一步生成2-氨基-3-氰基-4-芳基-7,7-二甲基-5-氧代-4H-5,6,7,8-四氢苯并[b]吡喃.该方法具有产率高、操作简便、对环境友好、催化剂可重复使用等优点.     

An efficient and practical synthesis of bis(indolyl)methanes catalyzed by aminosulfonic acid under ultrasound

Synthesis of bis(indolyl)methanes via electrophilic substitution reactions of indoles with aromatic aldehydes and ketones catalyzed by aminosulfonic acid was carried out in 23-96% yield at 30-38 degrees C in EtOH aqueous solution under ultrasound irradiation.     

Improved synthesis of chalcones under ultrasound irradiation

Claisen-Schmidt condensation of acetophenone with aromatic aldehydes catalyzed by pulverized KOH and KF-Al2O3 results chalcones in 52-97% and 83-98% yields respectively in alcoholic solvent under ultrasound irradiation.