STUDIES ON THE BIOMIMETIC PREPARATION OF THE SARPAGAN RING SYSTEM - ATTEMPTS TO APPLY THE SPONTANEOUS BIOGENETIC-TYPE CYCLIZATION OF VAN TAMELEN TO BOND FORMATION BETWEEN C-5 AND C-16 IN THE CORYNANTHEINE SERIES

摘要

Attempts were made to apply the spontaneous ''biogenetic-type cyclization'' of van Tamelen to the preparation of the sarpagan ring system by utilizing indolo[2,3-a]quinolizidines 10, 11, 12, and 14. The fact that the spontaneous ''biogenetic-type cyclization'' did not take place casts some doubt on the correctness of the earlier results. Copyright (C) 1996 Elsevier Science Ltd [References: 37]