SYNTHESIS AND POLYMERIZATION OF ANTI-BREDT, NITROGEN-BRIDGEHEAD BICYCLIC URETHANES

Persistent Link:
http://hdl.handle.net/10150/282326
Title:
SYNTHESIS AND POLYMERIZATION OF ANTI-BREDT, NITROGEN-BRIDGEHEAD BICYCLIC URETHANES
Author:
El-Shekeil, Ali Gamaan Salim
Issue Date:
1980
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Three nitrogen-bridgehead, bicyclic urethanes, 1-aza-8-oxa-bicyclo[4.3.0]nonan-9-one, I, 1-aza-3-oxabicyclo[3.3.1]nonan-2-one, II, and 1-aza-6-oxabicyclo[3.2.1]octan-7-one, III, were synthesized. UNFORMATTED TABLE OR EQUATION OMITTED - PLEASE SEE DISSERTATION. Contrary to popular opinion and in formal disagreement with Bredt's Rule, conformationally strain-free bicyclic urethanes II and III are stable because of N-C=O -O resonance interaction. The demand of the carbonyl for electrons is satisfied by N and O atoms. Urethane II was synthesized by cyclization of 3-chloroformyloxymethylpiperidine hydrotosylate using triethylamine or by refluxing 3-hydroxymethylpiperidinocarbamoyl chloride with excess triethylamine. To satisfy the N-C = 0 and O-C = 0 electron donation, the molecule does not exist in the two-chair form other [3.3.1] systems do, but in a form between the two-chair, boat-chair and flat-chair forms. Its low carbonyl stretching frequency, resistance to hydrolysis and resistance to ring-opening polymerization, all show that the molecule is not strained. 1-Aza-6-oxabicyclo[3.2.1]octan-7-one, III, was synthesized by the reaction of 3-hydroxypiperidinocarbamoyl chloride with four equivalents of triethylamine. It absorbed at 1770 cm⁻¹, 20 cm⁻¹ higher than Ḭ. Water hydrolyzed it at room temperature and phosphoric acid polymerized it at 105°, but it resisted ring-opening polymerization by potassium t-butoxide and p-toluenesulfonic acid in DMSO. As a reference, Ḭ was synthesized in five ways. It was obtained by the action of triethylamine on 2-chloroformyloxymethylpiperidine hydrostosylate, by reacting a mixture of triethylamine. phosgene and 2-hydroxymethylpiperidine, and by refluxing ethylene carbonate, diphenylcarbonate or di-t-butyl tricarbonate with 2-hydroxymethylpiperidine. Urethane I was stable in boiling water for 24 hr, and aqueous sodium hydroxide for two days. It showed no signs of polymerization after heating for extended periods with p-toluenesulfonic acid, phosphoric acid or potassium t-butoxide. The rearrangements of chloroformyloxypiperidines to hydroxypiperidinocarbamoyl chlorides were performed, and unsuccessful attempts were made to synthesize 1-aza-3-oxabicyclo[2.2.2]nonan-2-one.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Urethanes.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Hall, H. K. Jr.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleSYNTHESIS AND POLYMERIZATION OF ANTI-BREDT, NITROGEN-BRIDGEHEAD BICYCLIC URETHANESen_US
dc.creatorEl-Shekeil, Ali Gamaan Salimen_US
dc.contributor.authorEl-Shekeil, Ali Gamaan Salimen_US
dc.date.issued1980en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThree nitrogen-bridgehead, bicyclic urethanes, 1-aza-8-oxa-bicyclo[4.3.0]nonan-9-one, I, 1-aza-3-oxabicyclo[3.3.1]nonan-2-one, II, and 1-aza-6-oxabicyclo[3.2.1]octan-7-one, III, were synthesized. UNFORMATTED TABLE OR EQUATION OMITTED - PLEASE SEE DISSERTATION. Contrary to popular opinion and in formal disagreement with Bredt's Rule, conformationally strain-free bicyclic urethanes II and III are stable because of N-C=O -O resonance interaction. The demand of the carbonyl for electrons is satisfied by N and O atoms. Urethane II was synthesized by cyclization of 3-chloroformyloxymethylpiperidine hydrotosylate using triethylamine or by refluxing 3-hydroxymethylpiperidinocarbamoyl chloride with excess triethylamine. To satisfy the N-C = 0 and O-C = 0 electron donation, the molecule does not exist in the two-chair form other [3.3.1] systems do, but in a form between the two-chair, boat-chair and flat-chair forms. Its low carbonyl stretching frequency, resistance to hydrolysis and resistance to ring-opening polymerization, all show that the molecule is not strained. 1-Aza-6-oxabicyclo[3.2.1]octan-7-one, III, was synthesized by the reaction of 3-hydroxypiperidinocarbamoyl chloride with four equivalents of triethylamine. It absorbed at 1770 cm⁻¹, 20 cm⁻¹ higher than Ḭ. Water hydrolyzed it at room temperature and phosphoric acid polymerized it at 105°, but it resisted ring-opening polymerization by potassium t-butoxide and p-toluenesulfonic acid in DMSO. As a reference, Ḭ was synthesized in five ways. It was obtained by the action of triethylamine on 2-chloroformyloxymethylpiperidine hydrostosylate, by reacting a mixture of triethylamine. phosgene and 2-hydroxymethylpiperidine, and by refluxing ethylene carbonate, diphenylcarbonate or di-t-butyl tricarbonate with 2-hydroxymethylpiperidine. Urethane I was stable in boiling water for 24 hr, and aqueous sodium hydroxide for two days. It showed no signs of polymerization after heating for extended periods with p-toluenesulfonic acid, phosphoric acid or potassium t-butoxide. The rearrangements of chloroformyloxypiperidines to hydroxypiperidinocarbamoyl chlorides were performed, and unsuccessful attempts were made to synthesize 1-aza-3-oxabicyclo[2.2.2]nonan-2-one.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectUrethanes.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorHall, H. K. Jr.en_US
dc.identifier.proquest8018959en_US
dc.identifier.oclc7628122en_US
dc.identifier.bibrecord.b13471570en_US
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