Total Synthesis Of Bio-Active Natural Products Microcarpalide, Synargentolide A, Jaspine B And Anamarine
Electronic Theses of Indian Institute of Science
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Title |
Total Synthesis Of Bio-Active Natural Products Microcarpalide, Synargentolide A, Jaspine B And Anamarine
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Creator |
Penchalaiah, Kamala
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Subject |
Organics Synthesis
Microcarpalide Synargentolide Jaspine B Chiral Building Blocks Anamarine Pachastrissamine Hydroxy Cyclopentenone Organic Chemistry |
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Description |
The thesis entitled “Total synthesis of bio-active natural products microcarpalide, synargentolide A, jaspine B and anamarine.” demonstrates the utility of chiral pool tartaric acid as the source in the synthesis of bio-active natural products. The thesis was divided into four sections. Section I of the thesis deals with the enantiodivergent synthesis of microcarpalide from tartaric acid. Microcarpalide is a 10-membered lactone of polyketide origin isolated from the fermentation broths of an unidentified endophytic fungi, found to be weekly cytotoxic to mammalian cells and acts as a microfilament discrupting agent. Stereoselective approach for the synthesis of ()-microcarpalide is described from D- and L-tartaric acids, while enantiodivergent approach for the synthesis of both enantiomers is described from L-tartaric acid using ring closing metathesis as the Scheme 2: Enantiodivergent total synthesis of microcarpalide. In section II of the thesis, stereoselective synthesis of synargentolide A is described. Synargentolide A is a polyhydroxy -lactone, isolated from Syncolostemon argenteus, which was founf to exhibit cytotoxic and antitumor properties. Stereoselective synthesis of synargentolide A was accomplished, starting from L-tartaric acid employing, Keck and Brown allylations and ring closing metathesis, as the key steps. Scheme 3: Stereoselective total synthesis of ()-synargentolide A. Section III of the thesis deals with the synthesis of ()-jaspine B. Pachastrissamine (jaspine B), is an anhydrophytoshingosine derivative, isolated from marine sponges Pachastrissa and Jaspis speces. Pachastrissamine was shown to exhibit cytotoxicity (IC 50 0.01 g/mL) against P388, A549, HT29, and MEL28 cell lines. Enantioselective synthesis of jaspine B is accomplished from L-tartaric acid employing, Keck allylation, acid mediated formation of tetrahydrofuran, and olefin cross metathesis as the key reactions. In section IV of the thesis, enantioselective synthesis of ()-anamarine is described. Anamarine is a polyhydroxy -lactone isolated from the flowers and leaves of Peruvian hyptis, possessing cytotoxicity against human tumor cell lines. Enantioselective synthesis of -anamarine is accomplishedelaboration of hitherto unknown -keto phosphonate derived from tartaric acid amide. In an appendix for the thesis, enantiodivergent synthesis for 4-siloxy-pent-2-enone was described. The usefulness of asymmetric aldol reaction is exemplifiedin this section. hydroxy amide synthesized from crotonaldehyde is suitably elaborated to the diene which on RCM yielded 4-silyloxycyclopent-2-enone. Further synthetic modification of this compound afforded the other enantiomer. Scheme 6: Enantiodivergent synthesis of hydroxy cyclopentenones. (For structural formula pl the abstract pdf file) |
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Contributor |
Prasad, Kavirayani R
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Date |
2013-05-23T10:29:51Z
2013-05-23T10:29:51Z 2013-05-23 2011-08 |
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Type |
Thesis
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Identifier |
http://hdl.handle.net/2005/2007
http://etd.ncsi.iisc.ernet.in/abstracts/2597/G24987-Abs.pdf |
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Language |
en_US
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Relation |
G24987
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