Annulation Strategies for Benzo[<i>b</i>]fluorene Synthesis:  Efficient Routes to the Kinafluorenone and WS-5995 Antibiotics
                                
                                    
                                        作者:Ghassan Qabaja、Graham B. Jones                                    
                                    
                                        DOI:10.1021/jo0056186
                                    
                                    
                                        日期:2000.10.1
                                    
                                    Intramolecular palladium-mediated arylation approaches to benzo[b]fluorenes have been investigated. The methodology has been applied in a short synthesis of tri-O-methylkinafluorenone, providing an effective alternative td Friedel-Crafts-based approaches. During the course of this work, an acid-promoted quinolactonization of naphthoquinones was also developed, providing direct access to either ortho or para isomers as desired. Application of this methodology in syntheses of the antibiotics WS-5995A, WS-5995C, and functional analogues was demonstrated, and antitumoral activity of this class was determined.