O-Methyl norbelladine

In the first the mode of incorporation of the amino phenol O-methyl-norbelladine 343 into 10 was examined. Thus, tritium labels were inserted ortho and para to the phenolic hydroxy groups of 343 by base-catalyzed exchange with tritiated water under conditions ensuring equal labeling in all exchangeable positions. Norpluviine biosynthetized from multiply labeled 343 in Texas daffodil was selectively degraded to locate the tritium labels. 

The fact that more than 50% of the tritium is retained suggests that O-methyl-norbelladine is incorporated into narciclasine via path a rather than path b and this conclusion was confirmed by degradation to show that the tritium in narciclasine resides at both C(2) and C(4) as would be expected. 

Secondary cyclization is produced by an oxidative coupling of O-methyl-norbelladine. 

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