A regioselective synthesis of aryl substituted arylacetates through ring transformation by ethyl levulinate
作者:Ramendra Pratap、Vishnu Ji Ram
DOI:10.1016/j.tetlet.2006.05.071
日期:2006.7
A regioselective synthesis of sterically hindered ethyl arylacetates in one step through ring transformation of suitably functionalized 6-aryl-3,4-disubstituted-2H-pyran-2-ones with ethyl levulinate at room temperature in excellent yields is described.
Acetyltrimethylsilane: A Novel Reagent for the Transformation of 2<i>H</i>-Pyran-2-ones to Unsymmetrical Biaryls
作者:Atul Goel、Deepti Verma、Manish Dixit、Resmi Raghunandan、P. R. Maulik
DOI:10.1021/jo052085y
日期:2006.1.1
An expeditioussynthesis of unsymmetrical biaryls functionalized with electron-withdrawing or -donating substituents is described and illustrated by carbanion-induced ring transformation of 2H-pyran-2-one using acetyltrimethylsilane (ATMS) as a novel reagent in good yield. The novelty of the reaction lies in the creation of an aromatic ring from 2H-pyran-2-ones via two-carbon insertion from ATMS used
Synthesis of Benzocyclobutanes through Ring Transformation Reactions of 2<i>H</i>-pyran-2-ones
作者:Vishnu Ji Ram、Diptesh Sil、Ashoke Sharon、Ramendra Pratap、Prakas R. Maulik
DOI:10.1055/s-2004-831292
日期:——
A one-pot synthesis of benzocyclobutane (3a-n) has been developed through base-induced ring transformation reactions of 6-aryl-4-substituted-2H-pyran-2-one-3-carbonitriles (1a-c) and methyl 6-aryl-4-methylsulfanyl-2H-pyran-2-one-3-carboxylate (1d) by cyclobutanone.
Regioselective Syntheses of Functionalized 2-Aminopyridines and 2-Pyridinones through Nucleophile-Induced Ring Transformation Reactions
作者:Atul Goel、Fateh V. Singh、Ashoke Sharon、Prakas R. Maulik
DOI:10.1055/s-2005-862365
日期:——
An efficient one-pot synthesis of 2-amino-6-aryl-4-methylsulfanylpyridines and 6-aryl-3-cyano-4-methylsulfanyl-2(1H)-pyridinone has been illustrated through ring transformation of 6-aryl-3-cyano-4-methylsulfanyl-2H-pyran-2-ones by urea through different reaction conditions. Various solvents and bases were employed to selectively prepare either 2-aminopyridines or 2-pyridinones. In case of direct fusion of 2H-pyran-2-one with urea in solvent-free conditions, both the products were obtained in 1:1 ratio, while the reaction in pyridine at reflux temperature exclusively afforded 2-aminopyridine in 80-90% yield. The reaction of 6-aryl-3-carbomethoxy-4-methylsulfanyl-2H-pyran-2-ones with urea at 150 °C afforded 2-pyridinone derivatives in good yield (70-80%).
Regioselective Synthesis of Highly Functionalized Biaryls through Carbanion Induced Ring Transformation of 2<i>H-</i>Pyran-2-ones
作者:Vishnu Ji Ram、Abhishek Shanker Saxena、Atul Goel
DOI:10.1055/s-2002-33538
日期:——
An expedient synthesis of highly functionalized unsymmetrical biaryls 3 of which one of the two phenyl rings substituted with carbomethoxy, amino and nitrile functionalities is described and illustrated by carbanion induced ring transformation of 6-aryl-3-carbomethoxy-4-methylsulfanyl-2H-pyran-2-one 1 using malononitrile 2 as a source of carbanion in moderate yield.