A Convenient Synthesis of 5-Oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran Derivatives Catalyzed by KF-Alumina
摘要:
A series of 5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran derivatives were prepared by the reaction of arylmethylidenemalononitriles or 2-cyano-3-aryl-1-acrylate with 5,5-dimethyl- 1, 3-cyclohexanedione (dimedone) in DMF at room temperature catalyzed by KF-alumina. The structure of the product was confirmed by X-ray analysis.
Uncatalyzed Reactions in Aqueous Media: Three-Component, One-Pot, Clean Synthesis of Tetrahydrobenzo[b]pyran Derivatives
作者:Sunita B. Bandgar、Babasaheb P. Bandgar、Balaji L. Korbad、Jalinder V. Totre、Sachin Patil
DOI:10.1071/ch06461
日期:——
The synthesis of various tetrahydrobenzo[b]pyran derivatives has been carried out by means of an uncatalyzed, three-component, one-pot clean condensation of aromatic aldehydes, reactive methylene compounds, and dimidone in aqueous medium. Simple workup, and mild and neutral conditions that give quantitative yields of products in pure form, are the attractive features of this method.
One‐Pot Synthesis of 2‐Amino‐4‐aryl‐3‐carbalkoxy‐7,7‐dimethyl‐5,6,7,8‐tetrahydrobenzo[<i>b</i>]pyran Derivatives Catalyzed by KF/Basic Al<sub>2</sub>O<sub>3</sub>Under Ultrasound Irradiation
作者:Ji‐Tai Li、Wen‐Zhi Xu、Li‐Chao Yang、Tong‐Shuang Li
DOI:10.1081/scc-200043233
日期:2004.1
Synthesis of 2-amino-4-aryl-3-carbalkoxy-7,7-dimethyl-5-oxo-5,6,7,8-tertrahydrobenzo[b]pyran derivatives was carried out in 81-98% yields by one-pot condensation of aromatic aldehydes with cyanoacetic esters and 5,5-dimethyl-1,3-cyclohexanedione catalyzed by KF/basic Al2O3 at room temperature under ultrasound irradiation.
Diammonium Hydrogen Phosphate: An Efficient and Versatile Catalyst for the One‐Pot Synthesis of Tetrahydrobenzo[<i>b</i>]pyran Derivatives in Aqueous Media
Diammonium hydrogen phosphate was used as a mild, efficient, neutral, and cheap catalyst for the synthesis of various 4H-benzo[b]pyran derivatives via a one-pot, three-component condensation of aromatic aldehydes, active methylene compounds, and dimedone in aqueous media.
Efficient Synthesis of Tetrahydrobenzo[<i>b</i>]pyrans under Solvent‐Free Conditions at Room Temperature
A range of tetrahydrobenzo[b]pyrans have been synthesized in very good yields under solvent-free conditions by grinding alpha-cyanocinnamonitrils or beta-cyano-beta-carbethoxy styrene and 5,5-dimethyl-1,3-cyclohexanedione in the presence of TEBA as catalyst. The short reaction time, cleaner reaction, and easy workup make this protocol practical and economically attractive.
A Convenient Synthesis of 5-Oxo-5,6,7,8-tetrahydro-4<b><i>H</i></b>-benzo-[b]-pyran Derivatives Catalyzed by KF-Alumina
作者:Xiang-Shan Wang、Da-Qing Shi、Shu-Jiang Tu、Chang-Sheng Yao
DOI:10.1081/scc-120015567
日期:2003.3
A series of 5-oxo-5,6,7,8-tetrahydro-4H-benzo-[b]-pyran derivatives were prepared by the reaction of arylmethylidenemalononitriles or 2-cyano-3-aryl-1-acrylate with 5,5-dimethyl- 1, 3-cyclohexanedione (dimedone) in DMF at room temperature catalyzed by KF-alumina. The structure of the product was confirmed by X-ray analysis.