FIG. 6.

¹H NMR and ¹³C NMR data for different protoanemonins. The chemical shifts δ and the coupling constants J of 2-chloroprotoanemonin were determined with CD₃OD as the solvent. ¹H and ¹³C NMR data for 3-bromoprotoanemonin with CDCl₃ as the solvent were taken from de March et al. (8). ¹H NMR data for protoanemonin with CD₃OD as the solvent were taken from Blasco et al. (3); ¹³C-NMR data with CDCl₃ as the solvent were taken from de March et al. (8).