I. Generation of dibromocarbene under neutral conditions; II. Generation and reactions of 11-carbena[4.4.1]propella-3,8-diene; III. The oxidation of cyclopropylidenes

dc.contributor.advisor Philip M. Warner
dc.contributor.author Gurumurthy, Ramaswamy
dc.contributor.department Chemistry
dc.date 2018-08-16T19:27:04.000
dc.date.accessioned 2020-07-02T06:10:53Z
dc.date.available 2020-07-02T06:10:53Z
dc.date.copyright Sun Jan 01 00:00:00 UTC 1989
dc.date.issued 1989
dc.description.abstract <p>Most of the methods of generation of dihalocarbenes involve basic media which are not ideal for reactions with compounds containing base-sensitive groups like -OAc. In an effort to generate:CBr[subscript]2 under neutral conditions, we explored the thermolysis and photolysis of 10,10-dibromotricyclo ( deca-2,4-diene. Both methods generated:CBr[subscript]2 in good yields, as evidenced by the formation of dibromocyclopropane adducts with olefins like 2-pentene and cyclohexene;In an effort to study whether the tricyclic carbene, 11-carbena (4.4.1) propella-3,8-diene, ring opens to the corresponding allene, we generated the "free" carbene by LiOCH[subscript]3 decomposition of N-Nitroso-N- (4.4.1) -propella-3,8-dienyl-11-urea. Analysis of the product mixture did not indicate any allene derived product. In the course of this study we postulated a methanol induced ring opening of cyclopropyl diazonium ion to a diazo compound and discovered an unusual regioselectivity of nitrosation of norcarane ureas;Oxidation of carbenes with molecular oxygen yields intermediates such as carbonyl oxides and dioxiranes. These intermediates were orginally postulated in ozonolysis of alkenes. In recent years, many of these intermediates, prepared by the oxidation of carbenes and modified Baeyer-Villiger oxidation of ketones, have been studied spectroscopically (UV, IR, [superscript]1H NMR). In view of this, and based on the results of the oxidation of cyclopropyllithiums, we undertook a study of the oxidation of lithiumhalocyclopropanes (cyclopropylidenes). Low temperature [superscript]13C NMR study of this oxidation showed evidence for carbonyl oxide, dioxirane and bromoperoxylithium intermediates. Ours is the first report of [superscript]13C NMR spectra of carbonyl oxides and also coexistence of dioxiranes and carbonyl oxides in solution. The intermediates were also trapped by reagents such as n-BuLi and methanol.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/rtd/9046/
dc.identifier.articleid 10045
dc.identifier.contextkey 6348112
dc.identifier.doi https://doi.org/10.31274/rtd-180813-11906
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath rtd/9046
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/82102
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/rtd/9046/r_9003526.pdf|||Sat Jan 15 02:27:29 UTC 2022
dc.subject.disciplines Organic Chemistry
dc.subject.keywords Chemistry
dc.subject.keywords Chemistry
dc.subject.keywords Organic
dc.title I. Generation of dibromocarbene under neutral conditions; II. Generation and reactions of 11-carbena[4.4.1]propella-3,8-diene; III. The oxidation of cyclopropylidenes
dc.type article
dc.type.genre dissertation
dspace.entity.type Publication
relation.isOrgUnitOfPublication 42864f6e-7a3d-4be3-8b5a-0ae3c3830a11
thesis.degree.level dissertation
thesis.degree.name Doctor of Philosophy
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