DEFENSE-MECHANISMS OF ARTHROPODS .149. SYNTHESIS AND ABSOLUTE-CONFIGURATION OF 2 DEFENSIVE ALKALOIDS FROM THE MEXICAN BEAN BEETLE, EPILACHNA-VARIVESTIS

Syntheses of (2S,12'R)-2-(12'-aminotridecyl)-pyrrolid (1) and (2S,12'R )-1-(2 ''-hydroxyethyl)-2-(12'-aminotridecyl)-pyrrolidine (2), two def ensive alkaloids recently isolated from the Mexican bean beetle, Epila chna varivestis, are described. By a comparison of H-1 NMR data of MTP A derivatives of natural alkaloid 2 with those of the synthetic standa rd, we confirm the (2S,12'R) configuration previously suggested for th is alkaloid. Further support of these assignments was provided by the synthesis and H-1 NMR investigation of (2S,12'S)-1, (2S,12'S)-2, and t heir MTPA derivatives. (C) 1997 Published by Elsevier Science Ltd.