(--)-Sparteine Mediated Asymmetric Synthesis Through Conjugate Addition of Allylic and Benzylic Organolithium Species: Development of a Methodology and Its Application Toward a Total Synthesis

Curtis, Michael David

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Description

Title

(--)-Sparteine Mediated Asymmetric Synthesis Through Conjugate Addition of Allylic and Benzylic Organolithium Species: Development of a Methodology and Its Application Toward a Total Synthesis

Author(s)

Curtis, Michael David

Issue Date

2000

Doctoral Committee Chair(s)

Beak, Peter

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Chemistry, Organic

Language

eng

Abstract

The synthetic utility of the methodology is demonstrated with the synthesis of diastereo-, and enantiomerically pure 2,3,4-trisubstituted gamma-lactams in high yield. In addition, conjugate addition of the allylic organolithium species with N-protected 4-pyridones provides high yields of the corresponding 1,4-addition adduct with high enantiomeric ratios (ers). The reaction is believed to proceed through an N-acyl pyridinium salt formed on reaction of N-protected pyridone with TMSCl. An organolithium species derived from N-Boc-N-( p-Methoxyphenyl)dimethylphenylsilyl-allylamine, stabilized with a silyl group rather than a phenyl, has been successfully employed in this lithiation-conjugate addition sequence. The enantioenriched products that arise on electrophilic substitution with N-protected pyridones are precursors to piperidine alkaloids. Moreover, this reaction has been applied as the key step in the total synthesis of an immediate precursor to the indolizidine alkaloid castanospermine.

Graduation Semester

2000

Type of Resource

text

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