Regioselective lactonization of naphthoquinones: synthesis and antitumoral activity of the WS-5995 antibiotics

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.