Date of Award

8-2002

Degree Type

Thesis

Degree Name

Master of Science in Landscape Architecture

Major

Chemistry

Major Professor

David G. young

Committee Members

David Baker, John Turner

Abstract

Different ways for the synthesis of anti-Bredt ring systems of natural products have been explored.

An intended Favorskii rearrangement-divinylcyclopropane rearrangement to lead to the bicyclo[4.3.1] decadiene ring system was not accomplished. An envisioned tandem cyclopropanation-divinycyclopropane rearrangement of 2,3-divinyhex-2-enol did not furnish the desired bicyclo[4.4.1]undecadiene system, either, because cyclopropane occurred on the exocyclic double bond.

In the course of cyclopropanation studies on various cyclohexenols, an α-silyl-α-diazoethyl acetate was employed as tether. It could be removed by protodesilylation or oxidative cleavage to give a 1-(carboxylic ester)-cyclopropane or a 1-(carboxylic easter)-1-hydroxy cyclopropane derivative, respectively. Cyclopropanation general occurred on the less substituted more electron rich double bond.

Epoxidation of 2,3-divinylhex-2-enol with subsequent Cope rearrangement furnished the anti-Bredt oxabicyclo[4.4.1]undecadiene system that could be transformed into its regioisomer by Ireland-Claisen rearrangement.

Studies of the ring-closing metathesis of a cobalt carbonyl complexed ynediene to give a 10- or 11-membered ring failed. Ring-closing metathesis of a vinylsilane furnished an eight-membered ring.

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