The development of a four component reaction and its application to the synthesis of diverse heterocyclic scaffolds and the total synthesis of alkaloid natural products : the total synthesis of roelactamine and efforts towards the syntheses of rosicine and pseudotabersonine
| dc.contributor.advisor | Martin, Stephen F. | en |
| dc.creator | Sunderhaus, James Dennis | en |
| dc.date.accessioned | 2010-06-04T14:44:24Z | en |
| dc.date.available | 2010-06-04T14:44:24Z | en |
| dc.date.issued | 2009-08 | en |
| dc.date.submitted | August 2009 | en |
| dc.description | text | en |
| dc.description.abstract | A four component reaction involving the coupling of functionalized aldehydes, amines, acid chlorides, and [pi]- and organometallic nucleophiles has been developed to prepare multifunctional substrates that may be employed in subsequent ring-forming reactions to generate diverse arrays of functionalized heterocyclic scaffolds. Allyl metals, Grignard reagents, silyl ketene acetals, silyl enol ethers, and silyloxy furans have been utilized as the nucleophile in the four component reaction (4CR). The 4CR has been sequenced with intramolecular Heck reactions, Diels-Alder and [3+2] cycloadditions, ring closing metathesis (RCM), and Dieckmann condensations to provide a number of diverse heterocyclic structures. The practical utility of this approach to diversity-oriented synthesis (DOS) was further exemplified by its application to the first total synthesis of the isopavine alkaloid roelactamine, which was completed in only four steps from commercially available materials. The application of this methodology towards the synthesis of the Aspidosperma alkaloids rosicine and pseudotabersonine is also presented. To this end, an imine pentadienylation/double RCM strategy has been adopted to rapidly access the pentacyclic core of the aspidospermine alkaloids. This sequence involved the use of a pentadienyl aluminum reagent, which was found to react with aryl imines to give branched products in good yields. | en |
| dc.description.department | Chemistry and Biochemistry | en |
| dc.format.mimetype | application/pdf | en |
| dc.identifier.uri | http://hdl.handle.net/2152/ETD-UT-2009-05-170 | en |
| dc.language.iso | eng | en |
| dc.subject | Diversity oriented synthesis | en |
| dc.subject | Multicomponent reaction | en |
| dc.subject | Isopavine alkaloids | en |
| dc.subject | Aspidosperma alkaloids | en |
| dc.title | The development of a four component reaction and its application to the synthesis of diverse heterocyclic scaffolds and the total synthesis of alkaloid natural products : the total synthesis of roelactamine and efforts towards the syntheses of rosicine and pseudotabersonine | en |
| dc.type.genre | thesis | en |
| thesis.degree.department | Chemistry and Biochemistry | en |
| thesis.degree.discipline | Chemistry | en |
| thesis.degree.grantor | The University of Texas at Austin | en |
| thesis.degree.level | Doctoral | en |
| thesis.degree.name | Doctor of Philosophy | en |