Afin de connaitre avec prkcision l'influence du pontage sur la conformation du squelette heptahClicCnique, nous avons CtudiC, par diffraction des rayons X, les composCs suivants : [7]htlickne, dimCthyl-3,15-[7]hClicene (lo), hClidne (

xanthones had 150 values of about 30PM. Biflavonoids and. xanthones were assayed for their ability to inhibit the breakdown of cyclic AMP by a corn': mercial beef-heart phosphodiesterase. ' Flavonoids have been reported ' to Most of the biflavonoids were active in have various pharmacological actions the micromolar range, while amento-[I, 2, 31, m e of which resemble those flavone was ten times as potent;, two of many inhibitors of cyclic nucleotide Downloaded by: University of Illinois. Copyrighted material.

Ausgehend von den Verbindungen (I) bzw. (IV) werden nach angegebenen Reaktionsfolgen die Phenanthrene (III) und (VI) dargestellt und zu dem Bis‐phenanthryl‐äthylen (VII) kondensiert.

Vollkommen stereospezifisch verläuft die Darstellung von (II) aus (I) unter Konfigurationsumkehr.