Repository logo
  • English
  • 中文
Log In
Have you forgotten your password?
  1. Home
  2. College of Science / 理學院
  3. Chemistry / 化學系
  4. The Study of the Synthesis of Two Different Types of Alkaloids. Synthesis of Aporphinoids- Lirioferine and BoldineI. Synthesis of Chiral Piperidines via Radical Cyclization of Acylsilanes
 
  • Details

The Study of the Synthesis of Two Different Types of Alkaloids. Synthesis of Aporphinoids- Lirioferine and BoldineI. Synthesis of Chiral Piperidines via Radical Cyclization of Acylsilanes

Date Issued
2009
Date
2009
Author(s)
Chu, Fang-Lan
URI
http://ntur.lib.ntu.edu.tw//handle/246246/187537
Abstract
We discussed the syntheses of two different types of plant alkaloids in this thesis. In part A, we aimed at total syntheses in two kinds of aporphine alkaloids, lirioferine and boldine. In part B, we developed a tactic about radical cyclization in polyhydroxylated piperidine synthesis. According to recent research, high affinities between aporphine alkaloids and 5-HT7 receptor were observed. In order to develop an useful synthestic process, we have synthesized amides with various substitutents. The isoquinoline skeleton was constructed through Bischler-Napieralski reaction, followed by asymmetric reduction of the imine intermediates with a Ru complex to form the only chiral center. Finally, we connected the two phenyl groups by Heck reaction and effectively obtained optically active aporphine alkaloids. Thus, starting from commercially available material, guaiacol, we successfully produced lirioferine with 9% yield and 70% e.e. in fourteen steps. Similarly, starting from isovialine, we successfully produced boldine with 6% yield and 62% e.e. in fourteen steps. In another direction, we used L-serine as a chiral template to synthesize a chiral acylsilane as radical cyclization precursor. We uesd a “Boc” group for the protection of the amino group. Because of A1,3 strain, the neighboring ester group was pushed into an axial position in the radical cyclization chair transition state. After intramolecular radical cyclization and Brook-rearrangement, the resulting silyloxy substituted cyclohexyl radical preferred to abstract H atom from equatorial position to avoid the axially oriented ester group. We obtained the cis isomer as major product. During our research, we used phenyl selenenyl group to replace bromide to overcome the difficulties of synthesizing the cyclization precursor. Moreover, we used mercury (II) chloride for hydrolyzing 1,3-dithiane protecting group selectively to yield acylsilane with no influence on the phenyl selenenyl group. Eventually, we successfully produced polyhydroxylated piperidine with 26% yield in ten steps. Furthermore, comparing with the system with a tosyl group on nitrogen, the cis-trans selectivity was raised to 3.6:1 from 3:1.
Subjects
aporphine
lirioferine
boldine
acylsilanes
radical
piperidine
Type
thesis
File(s)
Loading...
Thumbnail Image
Name

ntu-98-R96223169-1.pdf

Size

23.32 KB

Format

Adobe PDF

Checksum

(MD5):6849ce25ac614ee4ea751a6150546b33

臺大位居世界頂尖大學之列,為永久珍藏及向國際展現本校豐碩的研究成果及學術能量,圖書館整合機構典藏(NTUR)與學術庫(AH)不同功能平台,成為臺大學術典藏NTU scholars。期能整合研究能量、促進交流合作、保存學術產出、推廣研究成果。

To permanently archive and promote researcher profiles and scholarly works, Library integrates the services of “NTU Repository” with “Academic Hub” to form NTU Scholars.

總館學科館員 (Main Library)
醫學圖書館學科館員 (Medical Library)
社會科學院辜振甫紀念圖書館學科館員 (Social Sciences Library)

開放取用是從使用者角度提升資訊取用性的社會運動,應用在學術研究上是透過將研究著作公開供使用者自由取閱,以促進學術傳播及因應期刊訂購費用逐年攀升。同時可加速研究發展、提升研究影響力,NTU Scholars即為本校的開放取用典藏(OA Archive)平台。(點選深入了解OA)

  • 請確認所上傳的全文是原創的內容,若該文件包含部分內容的版權非匯入者所有,或由第三方贊助與合作完成,請確認該版權所有者及第三方同意提供此授權。
    Please represent that the submission is your original work, and that you have the right to grant the rights to upload.
  • 若欲上傳已出版的全文電子檔,可使用Open policy finder網站查詢,以確認出版單位之版權政策。
    Please use Open policy finder to find a summary of permissions that are normally given as part of each publisher's copyright transfer agreement.
  • 網站簡介 (Quickstart Guide)
  • 使用手冊 (Instruction Manual)
  • 線上預約服務 (Booking Service)
  • 方案一:臺灣大學計算機中心帳號登入
    (With C&INC Email Account)
  • 方案二:ORCID帳號登入 (With ORCID)
  • 方案一:定期更新ORCID者,以ID匯入 (Search for identifier (ORCID))
  • 方案二:自行建檔 (Default mode Submission)
  • 方案三:學科館員協助匯入 (Email worklist to subject librarians)

Built with DSpace-CRIS software - Extension maintained and optimized by 4Science