| Abstract: | Homoisoflavanones. IV. New constituents of the Eucomin Series of Eucomis bicolor. Four new homoisoflavanones, (E)-7-O-methyl-eucomin ( 2a ), (—)-7-O-methyleucomol ( 5 ), (+)-3,9-dihydro-eucomin ( 7a ) and 7-O-methyl-3,9-dihydro-eucomin ( 8 ), were isolated from the bulbs of Eucomis bicolor Bak. (Liliaceae). Their structures were determined by spectral data and synthesis. These compounds occur exclusively in the waxy material between the bulb leaves. Furthermore it was shown that only (Z)-eucomin ( 1b ) is genuine, (E)-eucomin ( 1a ) being an artefact. It is likely that 2a is also not genuine. A new method for a selective 7-O-methylation is described. |
