SYNTHETIC EFFORTS TOWARD FUMONISIN via AMINO ACID SCHIFF BASE METHODOLOGY

Persistent Link:
http://hdl.handle.net/10150/193674
Title:
SYNTHETIC EFFORTS TOWARD FUMONISIN via AMINO ACID SCHIFF BASE METHODOLOGY
Author:
Kim, Shang U
Issue Date:
2009
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Synthetic efforts toward fumonisin analog were described. These are accomplished via amino acid Schiff base methodology. These efforts can be divided three major phases. First, tandem reductive alkylation with DIBAL/TRIBAL and different types of organo-lithium or Grignard nucleophiles provided threo-amino alcohol with excellent stereoselecitivites (2-27:1). The reductive alkylation utilized most hydrocarbon nucleophiles, e.g. alkyl-, vinyl-, alkenyl-, phenyl-, and dienyl-, and afforded high selectivites unless donor solvents (e.g. THF and Et2O) were used. Second, syntheses of the protected threo-γ-amino-β-hydroxy aldehydes and their stereoselectivities were introduced. The reductive alkylated threo-amino allyl alcohol was transformed via Brown’s hydroboration/oxidation protocol with 9-BBN, followed by TEMPO oxidation to give the resultant aldehydes in reasonable yields. Then, TBDPS and Schiff base protected aldehyde was coupled with phenyl- and decyl Grignard reagents to obtain predominant 3,5-anti-diols (ca. 80:20 anti:syn), characterized by ¹³C NMR analysis of Rychnovsky’s 1,3-acetonide groups. Products can be useful analogues for fumonisin and 5-hydroxy-sphingosine due to their structural similarity. Third stage involved the synthesis of C₁₁-C₂₀ fragment analog of fumonisin. Chiral auxiliaries (e.g. Evans and Myers) were administrated for stereoselective methylation, Sharpless asymmetric dihydroxylation in the presence of (DHQ)2PHAL catalyst was performed to form 1,2- syn-diols, and the manipulation of protection/deprotection and Finklestein reaction furnished C₁₁-C₂₀ fragment analog of fumonisin.
Type:
text; Electronic Dissertation
Keywords:
chiral auxiliary; dihydroxylation; Fumonisin; reductive alkylation; sphingolipids
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Chemistry; Graduate College
Degree Grantor:
University of Arizona
Advisor:
Polt, Robin L
Committee Chair:
Polt, Robin L

Full metadata record

DC FieldValue Language
dc.language.isoENen_US
dc.titleSYNTHETIC EFFORTS TOWARD FUMONISIN via AMINO ACID SCHIFF BASE METHODOLOGYen_US
dc.creatorKim, Shang Uen_US
dc.contributor.authorKim, Shang Uen_US
dc.date.issued2009en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractSynthetic efforts toward fumonisin analog were described. These are accomplished via amino acid Schiff base methodology. These efforts can be divided three major phases. First, tandem reductive alkylation with DIBAL/TRIBAL and different types of organo-lithium or Grignard nucleophiles provided threo-amino alcohol with excellent stereoselecitivites (2-27:1). The reductive alkylation utilized most hydrocarbon nucleophiles, e.g. alkyl-, vinyl-, alkenyl-, phenyl-, and dienyl-, and afforded high selectivites unless donor solvents (e.g. THF and Et2O) were used. Second, syntheses of the protected threo-γ-amino-β-hydroxy aldehydes and their stereoselectivities were introduced. The reductive alkylated threo-amino allyl alcohol was transformed via Brown’s hydroboration/oxidation protocol with 9-BBN, followed by TEMPO oxidation to give the resultant aldehydes in reasonable yields. Then, TBDPS and Schiff base protected aldehyde was coupled with phenyl- and decyl Grignard reagents to obtain predominant 3,5-anti-diols (ca. 80:20 anti:syn), characterized by ¹³C NMR analysis of Rychnovsky’s 1,3-acetonide groups. Products can be useful analogues for fumonisin and 5-hydroxy-sphingosine due to their structural similarity. Third stage involved the synthesis of C₁₁-C₂₀ fragment analog of fumonisin. Chiral auxiliaries (e.g. Evans and Myers) were administrated for stereoselective methylation, Sharpless asymmetric dihydroxylation in the presence of (DHQ)2PHAL catalyst was performed to form 1,2- syn-diols, and the manipulation of protection/deprotection and Finklestein reaction furnished C₁₁-C₂₀ fragment analog of fumonisin.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectchiral auxiliaryen_US
dc.subjectdihydroxylationen_US
dc.subjectFumonisinen_US
dc.subjectreductive alkylationen_US
dc.subjectsphingolipidsen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorPolt, Robin Len_US
dc.contributor.chairPolt, Robin Len_US
dc.contributor.committeememberMash, Eugeneen_US
dc.contributor.committeememberPyun, Jeffreyen_US
dc.contributor.committeememberZheng, Zhipingen_US
dc.contributor.committeememberSmith, Marken_US
dc.identifier.proquest10240en_US
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