A formal totalsynthesis of the aglycon of gilvocarcinM is described. The synthesis is based on the construction of the key naphthalene 7 via a free radical addition–cyclization protocol followed by aromatization of the resulting α-tetralone. This highly functionalized aromatic system is coupled to the corresponding acid chloride 6 to afford ester 4, which by treatment with a catalytic amount of palladium
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.
Regioselective lactonization of naphthoquinones: synthesis and antitumoral activity of the WS-5995 antibiotics
作者:Ghassan Qabaja、Elisabeth M. Perchellet、Jean-Pierre Perchellet、Graham B Jones
DOI:10.1016/s0040-4039(00)00329-4
日期:2000.4
An acid promoted quinolactonization of naphthoquinones has been 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 analogs is demonstrated. Preliminary antitumoral activity of the analogs is presented together with electrochemical analysis. (C) 2000 Elsevier Science Ltd. All rights reserved.
Total synthesis and absolute stereochemical assignment of gilvocarcin M.