uu.seUppsala universitets publikationer
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Radical Cyclization Approaches to Pyrrolidines
Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för organisk kemi.
2002 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Five-membered rings are readily prepared by 5-exo-trig radical cyclization. This thesis is concerned with novel methodology for pyrrolidine synthesis. We have synthesised selenium containing radical precursors from aziridines and α-phenylseleno ketones, and cyclized them to 2,4- and 3,4-disubstituted pyrrolidines. A few examples of 5-exo-dig cyclization were also demonstrated. In another study we investigated the capacity of the nitrogen protecting group to direct diastereoselectivity in the formation of 2,4-disubstituted pyrrolidines. The diphenylphosphinoyl protecting group directed cyclization to occur in a highly cis-selective manner. When cyclizations were performed at 17 oC, cis/trans-ratios as high as 24/1 were obtained. In contrast, cyclization of the unprotected pyrrolidine precursor afforded the trans-diastereomer as the major product (cis/trans = 1/3.3 – 1/20). We also examined the use of a hydroxyl auxiliary for controlling diastereoselectivity in radical cyclization. The required selenium containing radical precursors were synthesised from 2-cyanoaziridines by addition of organometallic reagents, reduction of the resulting aziridine ketone, and benzeneselenol ring-opening of the aziridine. Cyclization at 17 oC produced 2,4-disubstituted pyrrolidines substantially enriched in the trans-isomer (cis/trans = 1/9 – 1/12). Novel radical cyclization approaches to thiazolines and pyrrolines were also tried.

The thesis also describes attempts to improve the Hassner aziridine synthesis by employing stannous chloride as a functional group tolerant reducing agent.

Ort, förlag, år, upplaga, sidor
Uppsala: Acta Universitatis Upsaliensis , 2002. , s. 59
Serie
Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1104-232X ; 702
Nyckelord [en]
Organic chemistry, Radical cyclization, diastereselectivity, pyrrolidine, pyrroline, thiazoline, aziridine
Nyckelord [sv]
Organisk kemi
Nationell ämneskategori
Organisk kemi
Forskningsämne
organisk kemi
Identifikatorer
URN: urn:nbn:se:uu:diva-1954ISBN: 91-554-5287-6 (tryckt)OAI: oai:DiVA.org:uu-1954DiVA, id: diva2:161543
Disputation
2002-04-26, the The Svedberg Lecture Hall at the Institute of Chemistry, Uppsala, 10:15
Opponent
Tillgänglig från: 2002-04-05 Skapad: 2002-04-05Bibliografiskt granskad

Open Access i DiVA

fulltext(420 kB)3835 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 420 kBChecksumma MD5
0dd9569359d72f7195263b7cf739619063605e85bad729788642339e650f9a965e307d94
Typ fulltextMimetyp application/pdf
Köp publikationen >>

Av organisationen
Avdelningen för organisk kemi
Organisk kemi

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 3835 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

isbn
urn-nbn

Altmetricpoäng

isbn
urn-nbn
Totalt: 946 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf