Dibenzocyclooctadiene lignans from Magnolia and Talauma (Magnoliaceae): Their absolute configuration ascertained by circular dichroism and X-ray crystallography and re-evaluation of previously published pyramidatin structures

Twelve dibenzocyclooctadiene lignans were isolated from the Magnoliaceae. Calculated and experimentally determined circular dichroism data together with X-ray crystallography were used for unequivocal identification of absolute configuration.