Biflavonoids. Part 5: Structure and Stereochemistry of the First Bibenzofuranoids

The rare series of biflavonoids with benzofuranoid constituent units is extended by identification of (2S)-2-deoxymaesopsin-(2→7)-(2R)-maesopsin, its 2R(C):2S(F)-enantiomer, (2R)-2-deoxymaesopsin-(2→7)-(2R)-maesopsin, and its 2S(C):2S(F)-enantiomer. The collective use of chiral resolution, NMR, X-ray analysis, CD and molecular modeling permit definition of the absolute configuration of all four stereoisomers.