Hydrogénation de sels de flavylium: formation de composés heptacycliques; structure radiocristallographique du [tétrahydro-10b,10c,16,16a-diméthyl-16,16a-méthylène-10b,16-5aH-di(benzo[1]pyranno)[4,3-b:3′,4′,-c;2,3:2′,3′]-benz[1]oxépinyl-5a]-2-phénol

Hydrogenation of Flavylium Salts: Formation of Heptacyclic compounds; X-Ray Crystal Structure of 2-10b,10c,16,16a-Tetrahydro-16,16a-dimethyl-10b,16-methylene-5aH-di1]benzopyrano4,3-b:3′,4′ -c; 2,3:2′,3′]1]benzoxepin-5a-yl]phenol The hydrogenation of flavylium salts 1 either by catalytic reduction or by chemical reduction afforded the unexpected heptacyclic compound 2 , the structure of which was determined by X-ray analysis. The latter was confirmed by ¹H-NMR and mass spectra.