The asymmetric synthesis of 2SI3S-and 2R,3S-3-methyl-2-phenyl-l,4-benzodioxane from (-) -ephedrine is reported. Comparison of the c.d. curves of these compounds with those of the natural ncolignans eusiderin and eusiderin C allows the assignment of 2R,3R configuration to eusiderin and of 2R,3S configuration to eusiderin C and eusiderin D.
The structures of five new metabolites, stemphyltoxins (I)‐(IV) [(Ia)‐(Ic), (II)] and stemphyperylenol (III), are elucidated by analysis of their 1H and 13C NMR spectra [the relative configuration of (II) is unknown].
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.