Thalictrum strictum

A tertiary base isolated from Thalictrum strictum was assigned a pavine structure based on the spectral data (27). Three methoxyl and one methylenedioxy functions were detected with the aid of mass spectroscopy. Structure 3 was proposed as the most probable representation for this new pavine alkaloid, which indeed is the first example of a pentasubstituted pavine base. However, when the reported aromatic proton chemical shifts (8 6.23, 6.36, and 6.54) were evaluated in the light of empirical rules about the H-NMR absorptions of pavine bases (Section V,B), and it seemed possible that the two upfield absorptions belong to H-4 and H-10 rather than to H-1 and H-10. Therefore, alternative structure 4 cannot presently be completely excluded from consideration. 

Occurrence Platicapnos spicata (42a), Thalictrum hazarica (54), Thalictrum minus (55), Thalictrum rugosum (51), Thalictrum strictum (56), Thalictrum thunbergii (55), Unonopsis stipitata (48) Synthesis see Refs. 29, 52, and 55 Pharmacology see Ref. 5/... 

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