A-Naphthaphenanthridine

On the basis of these results they assigned formula (II) to ehelerythrine, and this was confirmed by the further observation that dihydrocheler -thrine, m.p. 166-7°, on treatment with phloroglucinol and sulphuric acid and subsequent methylation of the dihydric phenolic base so formed, yields tetramethoxy-A -methyldihydro-a-naphthaphenanthridine (VI), m.p. 182-3°, also obtainable from sanguinarine. ... 

The nature of the nucleus in chelidonine and sanguinarine was established by Spath and Kuffner,i who showed that both alkaloids on distillation with zinc dust yielded a-naphthaphenanthridine (V), first prepared by Graebe, and on that basis formula (IV) was suggested for sanguinarine. 

The relationship between chelerythrine (II) and sanguinarine (IV) was also established by Spath and Kuffner, who showed that dihydro-chelerythrine (p. 278) and dihydrosanguinarine, C20H15O4N, m.p, 188-9°, prepared from the natural alkaloid, and obviously identical with the dihydro- -chelerythrine of Gadamer and Winterfeld (see above), on replacement of the methylenedioxy-groups by methoxyl groups yielded the same substance, viz., tetramethoxv-A-methyldihydro-a-naphthaphenanthridine (VI). 

Bisbenzylisoquinoline Alkaloids by Marshall Kulka The Cularine Alkaloids by R. H. F. Manske. a-Naphthaphenanthridine Alkaloids BY R. H. F. Manske The Erythrophleum Alkaloids by G. Dalma. The Aconitum and Delphinium Alkaloids by E. S. Stern... 

The a-naphthaphenanthridine (benzo[c]phenanthridine) alkaloids are derived from the tetracyclic system I ia which the terminal nuclei are fully... 

Finally, Spath and Kuffner (39) succeeded in showing that the alkoxyl groups in chelerythrine and sanguinarine occupy the same positions. For this purpose the feebly basic dihydro bases of Karrer (36), who regarded them as non-basic, were demethylenated with sulfuric acid in the presence of phloroglucinol. The dihydroxy compound from chelerythrine and the tetrahydroxy compound from sanguinarine were methylated with diazomethane, and in both cases the same tetramethoxydihydro-iV-methyl-a-naphthaphenanthridine (XVIII) was obtained. 

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