R. Amann, K. Arnold, D. Spitzner
Jan 25, 2006
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Influential Citations
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Journal
Liebigs Annalen
Abstract
The addition of the chiral nucleophiles Na-2 and Li-5 to pyridinium compounds 1 and the subsequent ring closure (Pictet-Spengler cyclization) to indoloquinolizines 3a and 7b, respectively, proceed stereoselectively (d.e. for 3a: 54%; for 7b: ≥95%). Proof for the absolute configuration of these products is provided by their CD spectral data and the transformation of 7b into the indole alkaloids (+)-vallesiachotamine [(Z)-6] and (-)-isovallesiachotamine [(E)-6].