Cascade synthesis of polyoxygenated 6H,11H-benzopyrano-[4,3-c]benzopyran-11-ones.
Naumov MI, Sutirin SA, Shavyrin AS, Ganina OG, Beletskaya IP, Bourgarel-Rey V, Combes S, Finet JP, Fedorov AY
2-(methoxymethoxymethyl)aryllead triacetates, obtained in situ from the corresponding arylboronic acids, reacted with 4-hydroxycoumarins, leading to 3-(2-methoxymethoxymethyl)aryl-4-hydroxycoumarin derivatives in good to high yields. These compounds underwent a cascade sequence of reactions, deprotection-halogenation-annulation, to afford polyoxygenated tetracyclic 6H,11H-benzopyrano-[4,3-c] benzopyran-11-ones in good yields. Some compounds showed a moderate cytotoxicity against human epithelial mammary HBL100 cells.Lire l‘article