A contribution to the asymmetric synthesis of isoquinolines: Concise stereoselective approach to (3S,4S)-6,7-dimethoxy-4-hydroxy-3-phenyl-1,2,3,4-tetrahydroisoquinoline
摘要:
A highly efficient stereoselective synthesis of (3S,4S)-6,7-dimethoxy-4-hydroxy-3-phenyl-1,2,3,4-tetrahydroisoquinoline 8 (e.e.=96%) starting from enantiomerically pure imine 3 is reported. (C) 1998 Elsevier Science Ltd. All rights reserved.
A Simple and Efficient Synthetic Route to Chiral Isopavines. Synthesis of (−)-O-Methylthalisopavine and (−)-Amurensinine
摘要:
The isopavinan alkaloids (-)-O-methylthalisopavine (7a) and (-)-amurensinine (7d) have been synthesized in good yield and high ee from the appropriate 1,2-diarylethylamine derivatives using optically active beta-amino alcohols as chiral support. This synthetic route employs as key steps the alkylation reaction of the azomethine derivatives 2 with Grignard reagents 1 and a novel one-pot double-intramolecular cyclization of the adequately functionalized 1,2-diarylethylamines 5 to afford a series of optically active isopavines 6a-d and 7a-d.