BACKGROUND Indolizidine alkaloids widely occur in nature and display interesting biological activity. This is the reason for which their total synthesis as well as the synthesis of non-natural analogues still attracts the attention of many research groups. To establish new straightforward accesses to these molecules is therefore highly desirable. RESULTS The ring closing metathesis (RCM) of e...

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 re...

The 1,6-annulated 2-pyridone motif is found in many biologically active compounds and its close relation to the indolizidine and quinolizidine alkaloid core makes it an attractive building block. A nickel-catalyzed C-H functionalization of 2-pyridones and subsequent cyclization affords 1,6-annulated 2-pyridones by selective intramolecular olefin hydroarylation. The switch between the exo- and e...

Castanospermine, an indolizidine alkaloid isolated from the seeds of the chestnuttree Castanospermumaustrale,has beenshownto prevent the normal glycosylationalPrOCessingof the v-fins-transformingglyco protein. v-fins-transformedcellsgrownin vitro in the presenceof castano spermine accumulate Immature forms of the glycoprotein that do not reach the cell surface. These treated cells revert to the...