Metal-Free Tandem Friedel–Crafts/Lactonization Reaction to Benzofuranones Bearing a Quaternary Center at C3 Position
                                
                                    
                                        作者:Long Chen、Feng Zhou、Tao-Da Shi、Jian Zhou                                    
                                    
                                        DOI:10.1021/jo300395x
                                    
                                    
                                        日期:2012.5.4
                                    
                                    A metal-free tandem Friedel-Crafts/lactonization reaction to 3,3-diaryl or 3-alkyl-3-aryl benzofuranones catalyzed by HClO4 was reported. A variety of tertiary alpha-hydroxy acid esters could readily react with substituted phenols to afford the desired products in rich diversity. The synthetic utility of the products was demonstrated by the synthesis of polycyclic compounds. H-1 NMR studies supported that this tandem reaction proceeded via tandem Friedel-Crafts/lactonization sequence.