The Total Syntheses of Basiliolide C, epi-Basiliolide C, and Protecting-Group-Free Total Syntheses of Transtaganolides C and D
The total syntheses of basiliolide C and previously unreported epi-basiliolide C are achieved by an Ireland–Claisen/Diels–Alder cascade. The development of a palladium catalyzed cross-coupling of methoxy alkynyl zinc reagents allows for the protecting-group-free syntheses of transtaganolides C and D. Syntheses of transtaganolides C and D are accomplished in a single operation to generate three rings, two all-carbon quaternary centers, and four tertiary stereocenters from a monocyclic, achiral precursor.
Additional Information© 2014 American Chemical Society. Received: August 19, 2014. Publication Date (Web): September 22, 2014. The authors wish to thank the NSF (Award 1265591), Amgen, the Gordon and Betty Moore Foundation, and Caltech for financial support. J.R.G. thanks the Rose Hill Foundation for a predoctoral fellowship. H.M.N. thanks the NSF and Ford Foundation for predoctoral fellowships. Prof. Giovanni Appendino and Prof. Eduardo Muñoz are acknowledged for the biological testing of synthetically derived transtaganolide C. Dr. Kei Murakami is acknowledged for his contribution to the preparation of racemic transtaganolides C and D. Dr. Alexander F. G. Goldberg and Mr. Robert A. Craig II are acknowledged for useful discussions regarding synthetic strategies. Ms. Katerina M. Korch and Mr. Corey M. Reeves are acknowledged for assistance in manuscript preparation. Dr. David Vander-Velde is acknowledged for NMR assistance.
Supplemental Material - jo501924u_si_001.pdf