Voacangine pseudoindoxyl

The structure of voaluteine (rupicoline, voacangine pseudoindoxyl) was deduced from physical measurements. Of diagnostic value was the shielded methyl of the methoxyl 3.30 ppm (see voacangine 3.73 ppm). Attempts to prove the structure by chemical degradation were not successful (14). Preliminary attempts to hydrolyze voaluteine with acid or base were not encouraging. Hydrolysis was slow and was accompanied by general decomposition. The crude amino acid fractions upon re-methylation with diazomethane yielded only traces of voaluteine (14). 

Whether these pseudoindoxyls are natural products or artifacts is still to be determined. Conversion of the parent alkaloid could take place either after collection and drying and/or during the workup. The latter point has been studied and voacangine has survived the extraction conditions which were used to isolate rupicoline 14a). 

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