New syntheses of (±)-tashiromine and (±)-epitashiromine via enaminone intermediates

Darren L Riley; Joseph P Michael; Charles B de Koning

doi:10.3762/bjoc.12.256

New syntheses of (±)-tashiromine and (±)-epitashiromine via enaminone intermediates

Beilstein J Org Chem. 2016 Dec 2:12:2609-2613. doi: 10.3762/bjoc.12.256. eCollection 2016.

Authors

Darren L Riley¹, Joseph P Michael², Charles B de Koning²

Affiliations

¹ Department of Chemistry, University of Pretoria, Pretoria 0028, South Africa; Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Wits 2050, Johannesburg, South Africa.
² Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Wits 2050, Johannesburg, South Africa.

Abstract

The syntheses of the naturally occurring indolizidine alkaloid (±)-tashiromine and its unnatural epimer (±)-epitashiromine are demonstrated through the use of enaminone chemistry. The impact of various electron-withdrawing substituents at the C-8 position of the indolizidine core on the preparation of the bicyclic system is described.

Keywords: alkaloid; enaminone; epitashiromine; indolizidine; tashiromine.