Synthesis applications of cationic aza-Cope rearrangements. Part 25. Total synthesis of Amaryllidaceae alkaloids of the 5,11-methanomorphanthridine type. Efficient total syntheses of (-)-pancracine and (.+-.)-pancracine
摘要:
Stereocontrolled total syntheses of the 5,11-methanomorphanthridine alkaloid pancracine in racemic (rac-1) and natural levorotatory form (1) are described. The key step is a Lewis acid-mediated aza-Cope rearrangement-Mannich cyclization reaction (9 --> 6, Scheme I).
Synthesis applications of cationic aza-Cope rearrangements. Part 25. Total synthesis of Amaryllidaceae alkaloids of the 5,11-methanomorphanthridine type. Efficient total syntheses of (-)-pancracine and (.+-.)-pancracine
摘要:
Stereocontrolled total syntheses of the 5,11-methanomorphanthridine alkaloid pancracine in racemic (rac-1) and natural levorotatory form (1) are described. The key step is a Lewis acid-mediated aza-Cope rearrangement-Mannich cyclization reaction (9 --> 6, Scheme I).
Stereoselective Synthesis of 3-Aryloctahydroindoles and Application in a Formal Synthesis of (−)-Pancracine
作者:Sunil V. Pansare、Rajinikanth Lingampally、Raie Lene Kirby
DOI:10.1021/ol902761a
日期:2010.2.5
A stereoselective synthesis of 3-aryloctahydroindoles from enantiomerically enriched γ-nitroketones has been developed. Reduction of imines derived form the nitroketones provides the trans-fused octhaydroindole motif selectively. The cis-octahydroindole skeleton is accessible by an invertive cyclization strategy involving a diastereomerically pure nitromesylate intermediate. This approach was employed