Cyclic sulfamidates as versatile lactam precursors. An evaluation of synthetic strategies towards (−)-aphanorphine
作者:John F. Bower、Peter Szeto、Timothy Gallagher
DOI:10.1039/b614999e
日期:——
led to the efficient asymmetric synthesis of (-)-aphanorphine is reported. Two routes to the key cyclic sulfamidate intermediate are described, the first was based on a chiral auxiliary approach and the second utilised asymmetric hydrogenation methodology. A range of C(3)-substituted lactams (, and ) were synthesised and evaluated as precursors for Pd(0) catalysed entries (based on (i) alpha-arylation
An Asymmetric Approach towards (-)-Aphanorphine and Its Analogues
作者:Pavel A. Donets、Jan L. Goeman、Johan Van der Eycken、Koen Robeyns、Luc Van Meervelt、Erik V. Van der Eycken
DOI:10.1002/ejoc.200801175
日期:2009.2
A short enantioselective approachtowards the alkaloid (-)-aphanorphine and its substituted analogues is described. The enantiomerically pure starting material for the synthesis was obtained by asymmetric hydrogenation in the presence of the Rh-(S)-PipPhos complex. Microwave-assisted Heck cyclization selectively provided the seven-membered 3-benzazepine ring. Further, the assembly of the tricyclic