Background. The Birch reduction of electron rich pyrroles does not occur readily. However, dissolving metal reduction with zinc under acidic conditions gives 3-pyrrolines (2,5-dihydropyrroles) in reasonable yield. This dissolving metal reduction was first reported by Knorr and Rabe in 1901 but since then has only been reported for the reduction of electron rich pyrroles. Results. The partial reduction of bicyclic -ketopyrrole derivatives has been performed under dissolving metal conditions with zinc and hydrochloric acid to give excellent yields of hexahydroindolizidines. This reduction method has been utilised for the diastereoselective synthesis of 5-alkylindolizidines and the stereoselectivity obtained is opposite to that of catalytic hydrogenation. Conclusion. An efficient stereoselective synthesis of indolizidine alkaloids has been developed from -ketopyrrole intermediates using a modified version of Knorr and Rabe's pyrrole reduction. © 2008 Gourlay et al; licensee Beilstein-Institut.

Item Type:	Refereed Article
Research Division:	Chemical Sciences
Research Group:	Organic chemistry
Research Field:	Natural products and bioactive compounds
Objective Division:	Expanding Knowledge
Objective Group:	Expanding knowledge
Objective Field:	Expanding knowledge in the chemical sciences
UTAS Author:	Gourlay, BS (Dr Brendon Gourlay)
UTAS Author:	Smith, Jason (Professor Jason Smith)
ID Code:	55279
Year Published:	2008
Web of Science® Times Cited:	14
Deposited By:	Chemistry
Deposited On:	2009-03-08
Last Modified:	2015-02-13
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