The vast majority of theses in this collection are open access and freely available. There are a small number of theses that have access restricted to the WWU campus. For off-campus access to a thesis labeled "Campus Only Access," please log in here with your WWU universal ID, or talk to your librarian about requesting the restricted thesis through interlibrary loan.
Date Permissions Signed
5-18-2011
Date of Award
2011
Document Type
Masters Thesis
Degree Name
Master of Science (MS)
Department
Chemistry
First Advisor
Vyvyan, James R.
Second Advisor
O'Neil, Gregory (Gregory W.)
Third Advisor
Raymond, Elizabeth A.
Abstract
The heliannuols are a family of allelochemicals that have been isolated from the common sunflower (Helianthus annuus). The 8-membered cyclic ether moiety found in many of the heliannuols is a rare motif in nature and provides a challenging synthetic target. It has been found that conformational constraint in the form of a Z olefin helps promote the cyclization of aryl epoxides to the 8-membered cyclic ether. Hiyama couplings of aryl iodides and cyclic vinyl siloxanes produce Z-styrenes in good to excellent yields. Due to the expense of the catalyst used for the synthesis of the siloxanes, an alternate pathway to the Z olefins utilizing vinyl cyclic boronic half acids was also pursued, but was ultimately unsuccessful. Due to the success of Hiyama couplings, the synthesis of glandulone B was pursued. The dimethoxyhydroquinone derivative of glandulone B was synthesized from an aryl iodide and cyclic vinyl siloxane in a 23% yield over 4 steps. Oxidation of the dimethoxyhydroquinone to glandulone B was explored.
Type
Text
DOI
https://doi.org/10.25710/tec1-h796
Publisher
Western Washington University
OCLC Number
729271407
Subject – LCSH
Natural products--Synthesis; Sunflowers; Allelopathic agents--Synthesis
Format
application/pdf
Genre/Form
masters theses
Language
English
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Recommended Citation
Engles, Courtney A., "Preparation of Z-substituted styrenes using hiyama and suzuki cross couplings: a synthesis of glandulone B" (2011). WWU Graduate School Collection. 110.
https://cedar.wwu.edu/wwuet/110