Michellamines A-C have been prepared by total synthesis in 7 and 16 linear steps from known and commercial materials, respectively. Key steps include i) palladium(0)-mediated biaryl coupling, ii) silver oxide promoted oxidative 1-naphthol coupling to an atropisomeric mixture of cross-ring quinones (indigoids), and iii) simultaneous per-debenzylation/reductive bleaching to the central 2,2′-binaphthol.
Bibliographical noteFunding Information:
Acknowledgments This work was supported by grant #CA-M284 awarded by the DHHS. A sample of natural michellamine B was kindly provided by Dr. Ven L. Narayanan of the Drug Synthesis & Chemistry Branch, Developmental Therapeutics Program, Division of Cancer Treatment, National Cancer Institute.
Copyright 2014 Elsevier B.V., All rights reserved.