Skip navigation
  • Home
  • Browse
    • Communities
      & Collections
    • Browse Items by:
    • Publication Date
    • Author
    • Title
    • Subject
    • Department
  • Sign on to:
    • My MacSphere
    • Receive email
      updates
    • Edit Profile


McMaster University Home Page
  1. MacSphere
  2. Open Access Dissertations and Theses Community
  3. Open Access Dissertations and Theses
Please use this identifier to cite or link to this item: http://hdl.handle.net/11375/5827
Title: Orchestration of Reactions of Glycoluril Templates
Authors: Cow, Christopher N.
Advisor: Harrison, Paul
Department: Chemistry
Keywords: Chemistry;Chemistry
Publication Date: Aug-1997
Abstract: <p>Glycoluril 1 has been shown to act as a template, facilitating intramolecular Claisen-type condensations between bound acyl units. Repetitive acylations, condensations, and functional group manipulations allow the synthesis of complex structures from simple starting materials. Thus, the natural product tetradec-2-enoic acid-4,5-epoxide 2 was prepared by condensation on 1 of decanoic acid with two units of acetate. The 1-(3'-oxodecanoyl) glycoluril 3 was prepared from 1 via 4. Conversion to the dodecenoyl derivative 5 (2 steps), followed by a second cycle of acetylation, condensation, reduction and dehydration provided tetradeca-2,4-dienoyl glycoluril 6. Direct cleavage to the carboxylic acid, followed by epoxidation gave 2. Mono- (7) and di-thio (8) analogues of 1 are readily prepared using Lawesson's reagent; this novel application of Lawesson's reagent can be extend to N-acylglycolurils, leading to monacylmonothio derivatives (9) in which thionation occurs at the least hindered urea carbonyl. The thio analogues 7 and 8 are more readily acylated than 1; acylation of 7 occurs exclusively on the NH site adjacent to sulfur to give 10. All diacetylthioglycolurils underwent the Claisen-like condensation reaction to give acetoacetyl thioglycoluril derivatives; 11 undergoes selective deprotonation of the acetyl group adjacent to oxygen to give a mixture of 12 and 13 (2.2:1). Crossed-Claisen condensations of both isomers of acetyl-butanoyl monothioglycoluril (14, 15) afforded 3-ketohexanoyl and 2-ethyl-3-ketobutanoyl thioglycolurils (16 and 17, 18 and 19, respectively). Condensation of 14 led to a highly selective crossed-Claisen condensation (16:17 6:1); while condensation of 15 led to a reversal of regioselectivity (18:19 0.75:1). The x-ray crystallographic structures of key compounds in the glycoluril cycle were compared in order to improve understanding of geometrical factors involved in the condensation reaction. Additionally, several reactions in the cycle, including the first acylation, the condensation, the reduction, and the cleavage reactions were investigated to find conditions which lead to improved yields.</p>
URI: http://hdl.handle.net/11375/5827
Identifier: opendissertations/1175
2525
1306345
Appears in Collections:Open Access Dissertations and Theses

Files in This Item:
File SizeFormat 
fulltext.pdf
Open Access
7.6 MBAdobe PDFView/Open
Show full item record Statistics


Items in MacSphere are protected by copyright, with all rights reserved, unless otherwise indicated.

Sherman Centre for Digital Scholarship     McMaster University Libraries
©2022 McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4L8 | 905-525-9140 | Contact Us | Terms of Use & Privacy Policy | Feedback

Report Accessibility Issue