Total Synthesis of (+)-nemorensic acid: En Route to (-)-callosine

An intramolecular oxime ether cyclopropane annulation developed in 2008 by Kerr has been shown to form 2,5-trans and 2,5-cis pyrrolidines in a stereodivergent fashion. When the oxime ether is functionalized with an enantioenhanced α-hydroxy substitutent and a leaving group, the pyrrolizidine core of (-)-callosine can be accessed in short order. Callosine is a structurally unique pyrrolizidine alkaloid isolated from Mexican flowering plant Senecio callosus. In an effort to complete the total synthesis, the total synthesis of (+)-nemorensic acid, the necic acid component of the callosine, has been established. Attempts at appending the ansa bridge via esterification and macrolactonization are discussed.

Name thesis:degree_name

M Sc

Discipline thesis:degree_discipline

Chemistry

Grantor dc:publisher

The University of Western Ontario

Year dc:date.issued

2016

Author dc:creator

• Vriesen, Matthew R

Advisor dc:contributor.advisor

• Michael Kerr

• nemorensic acid
• callosine
• total synthesis
• cyclopropane
• annulation

Language dc:language.iso

en_ca

Handle dc:identifier.uri

https://hdl.handle.net/20.500.14721/33725

OAI identifier oai:identifier

oai:uwo.scholaris.ca:20.500.14721/33725