The development of iterative and cascade methods for the rapid synthesis of ladder polyether natural products

I. The Development of Methods for the Iterative Synthesis of Polytetrahydropyrans An iterative method comprising chain homologation, epoxidation, 6-endo cyclization, and protiodesilylation was developed. Notable achievements include the development of a novel propargyl organocopper coupling method, and the complete control of stereoselectivity and regioselectivity during the iterative synthesis of a tristetrahydropyran. The synthesis of the tristetrahydropyran was achieved in 18 total operations. ... (1) homologation (2) epoxidation (3) cyclization (4) protiodesilylation ... II. The Development of a Cascade Synthesis of Polytetrahydropyrans with No Directing Groups at Ring Junctions Cascade approaches to trans-fused tetrahydropyrans were studied. After exploring acid-promoted cascade cyclizations of polyepoxysilanes and polyepoxides without directing groups, the base-promoted cascade cyclization of polyepoxysilanes was realized. In this method, as many as five operations take place in a single step to provide a tristetrahydropyran with no directing groups at any ring junctions. The synthesis of the tristetrahydropyran was accomplished in 11 steps. ...

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Heffron, Timothy Paul

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/1721.1/32478

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/32478