Synthesis and absolute configuration of 2-(12′-aminotridecyl)-pyrrolidine, a defensive alkaloid from the Mexican bean beetle, Epilachna varivestis

Abstract

Abstract The synthesis of 2-(12′-aminotridecyl)-pyrrolidine ( 1 ), a defensive alkaloid recently isolated from the Mexican bean beetle, Epilachna varivestis , is described. The (2 S ,12′ R ) configuration is assigned to this alkaloid by comparing the 1 H NMR spectrum of its ( S )-MTPA derivative with that of ( R )- and ( S )-MTPA [α-methoxy-α-(trifluoromethyl)phenylacetyl] derivatives of the synthetic sample. These results suggest that the seventeen carbon skeleton of 1 is acetate rather than proline derived.