Coumarins of theLibanotis buchtormensis

Conclusions

From the roots ofLibanotis buchtormensis (Fisch.) D.C. have been isolated the furocoumarins bergapten, isoimperatorin, a pyranocoumarin, xanthogallol, and a new coumarin buchtormin C₁₉H₂₀O₅, for which the structure (+)-3′-(β,β-dimethylacryloxy)-2′,2′-dimethyl-3′, 4′-dihydropyrano-5′, 6′:8, 7-coumarin has been proposed and confirmed by synthesis.