Enantioselective synthesis of 2,2,5-Tri- and 2,2,5,5-tetrasubstituted tetrahydrofurans and synthesis of diketopiperazine containing natural products

A chiral vinyl sulfoxide has been developed that undergoes highly diastereoselective Diels−Alder cycloadditions with various substituted furans in excellent yield. The cycloadducts can be stereoselectively transformed into tetrasubstituted tetrahydrofurans via ring-opening metathesis/cross-metathesis or oxidative cleavage and refunctionalization. A partial synthesis of the bioactive diketopiperazine containing natural product gliocladin C was achieved in nine steps, and 13.4% overall yield. The synthesis featured several novel transformations including the construction of the core structure by an elimination and nucleophilic addition sequence, followed by a Lewis acid promoted coupling with indole giving the key quaternary oxindole intermediate. A new protocol for intramolecular reductive coupling of the oxoindole and bis-unsaturated diketopiperazine led to successful construction of the hexacyclic skeleton.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Organic Chemistry

Grantor

The University of Texas at Austin

Year dc:date.issued

2012

Author dc:creator

• Benjamin, Noah Meyer

Advisor dc:contributor.advisor

• Martin, Stephen F

Committee members dc:contributor.committeemember

• Krische, Michael J
• Iverson, Brent L
• Brodbelt, Jennifer S
• Kerwin, Sean M
• Bielawski, Christopher W

• Diketopiperazine, Tetrahydrofuran, Noah Benjamin

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/2152/19501

OAI identifier oai:identifier

oai:repositories.lib.utexas.edu:2152/19501