Total synthesis of (-)-(alpha)-kainic acid via a diastereoselective methylenecyclopropane ring expansion

Mark E Scott; Mark Lautens

doi:10.1021/ol051003p

Total synthesis of (-)-(alpha)-kainic acid via a diastereoselective methylenecyclopropane ring expansion

Org Lett. 2005 Jul 7;7(14):3045-7. doi: 10.1021/ol051003p.

Authors

Mark E Scott¹, Mark Lautens

Affiliation

¹ Davenport Research Laboratories, Department of Chemistry, University of Toronto, Ontario, Canada.

PMID: 15987201
DOI: 10.1021/ol051003p

Abstract

[reaction: see text] A concise and enantioselective synthesis of (-)-(alpha)-kainic acid in 13 steps with an overall yield of 15% is reported. The pyrrolidine kainoid precursor with the required C2/C3 trans stereochemistry was prepared with excellent diastereoselectivity (>20:1) via a MgI(2)-mediated ring expansion of a tertiary methylenecyclopropyl amide. A selective hydroboration was then employed to set the remaining stereochemistry at the C4 position en route to (-)-(alpha)-kainic acid.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cyclization
Cyclopropanes / chemistry*
Indicators and Reagents
Kainic Acid* / analogs & derivatives
Kainic Acid* / analysis
Kainic Acid* / chemical synthesis
Kainic Acid* / chemistry
Molecular Structure
Stereoisomerism

Substances

Cyclopropanes
Indicators and Reagents
methylenecyclopropane
Kainic Acid