Enantioselective syntheses of two 5, 9E diastereomers of 223V, an alkaloid from the poison frog Dendrobates pumilio

Enantioselective syntheses of two 5, 9E diastereomers ( and ) of () are described. Neither corresponded on GC–MS and GC-FTIR analyses to alkaloid , previously tentatively proposed to be a 5,8-disubstituted indolizidine of the unusual 5, 9E relative stereochemistry. Synthetic (−)-(5, 9Z)-5-n-propyl-8-n-butylindolizidine () corresponds on GC–MS and GC-FTIR analyses to the natural indolizidine found in a pumilio from ‘Split Hill’, Panama.