Formal Synthesis of <i>Aspidosperma</i> Alkaloids via the Intramolecular [3 + 2] Cycloaddition of 2-Azapentdienyllithiums
作者:William H. Pearson、Aaron Aponick
DOI:10.1021/ol0602506
日期:2006.4.1
[reaction: see text] A formal synthesis of the Aspidosperma alkaloids aspidospermidine, aspidospermine, and quebrachamine is reported through an efficient preparation of Stork's penultimate intermediate. The key step of the sequence involved an intramolecular [3 + 2] cycloaddition of the 2-azapentadienyllithium 21 formed in situ from the corresponding imine 1, which after N-alkylation of the resulting