STUDIES OF ENZYME-MEDIATED REACTIONS .9. STEREOCHEMISTRY OF OXIDATIVE RING CLEAVAGE ADJACENT TO NITROGEN DURING THE BIOSYNTHESIS OF CHELIDONINE

Synthetic routes are devised leading to phenethylamine derivatives which are chiral at C-1 due to 3H-substitution. These (1R)- and (1S)-amines have high configurational purity (98% one enantiomer) and their absolute configurations are confirmed by studies with the amine oxidase from pea seedlings. (6R-3H1)-Scoulerine and the (6S-3H1)-isomer are synthesized from these phenethylamines and the products are used for incorporation experiments with Chelidonium majus plants. The results for tritium retention in the 2 series, and for the (6RS-3H1)-series, prove that cleavage of the bond between N and C-6 of stylopine which finally leads to chelidonine [alkaloid], occurs with stereospecific loss of the H-atom in Si-space.