Rhodium-catalyzed epoxide-opening cascades toward brevisin and hemibrevetoxin B

CHAPTER I. Rhodium-Catalyzed Epoxide-Opening Cascades: Formal Synthesis of (-)-Brevisin [chemical formula inserted] [Rh(CO)₂Cl]₂ was found to be an effective catalyst for endo-selective cyclizations and cascades of epoxy-(E)-enoate alcohols, thus enabling the synthesis of oxepanes and oxepanecontaining polyethers from di- and trisubstituted epoxides. Syntheses of the ABC and EF ring systems of (-)-brevisin via all endo-diepoxide-opening cascades using this method constitute a formal total synthesis and demonstrate the utility of this methodology in the context of the synthesis of marine ladder polyether natural products CHAPTER II. Synthetic Studies Toward Hemibrevetoxin B [chemical formula inserted] We report progress toward a biomimetic epoxide-opening cascade of the marine ladder polyether hemibrevetoxin B. Model studies demonstrate the ability of both [Rh(CO)₂Cl]₂ and cationic Rh(I) species to override the typical exo-directing of proximal methyl groups on in epoxy alcohol cyclizations for the synthesis of oxepanes. The synthesis of tri-epoxide cascade precursor and initial investigations toward an epoxide-opening cascade are described as well.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2014

Author dc:creator

• Armbrust, Kurt W. (Kurt Willes)

Advisor dc:contributor.advisor

• Timothy F. Jamison.

• Chemistry.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/93032

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/93032