Enantioenriched Allenylsilanes as Building Blocks for Stereocontrol in Organic Synthesis / Studies Towards the Total Synthesis of (-)-Dictyostatin

Ryan Brawn From: Camden, Maine, B.A. Bowdoin College, Spring 2003	Studies are being undertaken towards the total synthesis of marine macrolide (-)-dictyostatin. For isolation see: a) G. R. Pettit, Z. A. Cichacz, F. Gao, M. R. Boyd, J. M. Schmidt, J. Chem. Soc., Chem. Commun. 1994, 1111; b) G. R. Pettit, US 1995, USXXAM US 5430053 A 19950704. c) R. A. Isbrucker, J. Cummins, S. A. Pomponi, R. E. Longley, A. E. Wright, Biochem. Pharm. 2003, 66, 75. For previous syntheses see: a) I. Paterson et al., Angew.Chem. Int. Ed. 2004, 43, 4629; b) D. P. Curran et al., Angew. Chem. Int. Ed. 2004, 43, 4634. c) A. J. Phillips et al., J. Am. Chem. Soc. 2006, 128, 5340, d) P. V. Ramachandran et al., Org. Lett. 2007, 9, 157.
Methodology Enantioenriched allenylsilanes have been prepared on multigram sclaes using Johnson orthoester and Ireland Claisen strategies. These allenylsilanes are used as carbon nucleophiles in additions to C=X π bonds. See: R. A. Brawn, J. S. Panek Org. Lett. 2007, 9, 2689.