Title page for etd-0708117-174815


[Back to Results | New Search]

URN etd-0708117-174815
Author You-min Jhang
Author's Email Address axzimrat@hotmail.com.tw
Statistics This thesis had been viewed 5537 times. Download 0 times.
Department Chemistry
Year 2016
Semester 2
Degree Master
Type of Document
Language zh-TW.Big5 Chinese
Title Synthesis of Bicyclic Tetrahydrothiophene Derivatives
Date of Defense 2017-07-10
Page Count 115
Keyword
  • cyclopenta[c]thiophene
  • Ruthenium catalyzed ring-closing metathesis
  • Claisen / Overman rearrangement
  • Abstract Tetrahydrothiophene derivatives are commonly found in the structures of natural products, these biologically active tetrahydrothiophene derivatives can be used as medicinal drugs. Tetrahydrothiophene derivatives also can be used in nanomaterials and assist asymmetric organic synthesis. In the past literatures, synthesis methods such as Prins cyclization, Michael/ aldol reaction, Lewis acid catalysis, transition metal catalysis have been used by chemists to synthesize tetrahydrothiophene derivatives. In this thesis, a strategy based on the ring closing metathesis of functionalized diallyl sulfides to synthesize tetrahydrothiophene was proposed. Further utilization of Claisen / Overman rearrangement to modified its functional groups should allow the synthesis of bicyclic tetrahydrothiophene. A number of methods were attempted to synthesize bicyclopenta[c]thiophene derivatives, these including ene-carbonyl reaction, Prins cyclization, Cu(I)-mediated halogen-atom-transfer radical cyclization. However non of these reactions were successful. We infer that when synthesizing bicyclopenta[c]thiophene, the ring strain is perhaps too high to allow bicyclopenta[c]thiophene formation, or that sulfur atom could cause the loss of catalytic activity in transition metal-catalyzed reactions. Thus we converted the tethered aldehyde into allyl acetate with Grignard reagent and finally constructed the bicyclopenta[c]thiophene structure by ring-closing metathesis.
    Advisory Committee
  • Ching-Ching Yu - chair
  • Chian-Hui Lai - co-chair
  • Chia-Chun Chen - co-chair
  • Yu-Ya Lin - advisor
  • Files
  • etd-0708117-174815.pdf
  • Indicate in-campus at 3 year and off-campus access at 3 year.
    Date of Submission 2017-08-28

    [Back to Results | New Search]


    Browse | Search All Available ETDs

    If you have more questions or technical problems, please contact eThesys