Homoisoflavanone. IV. Neue Inhaltsstoffe der Eucomin‐Reihe von <i>Eucomis bicolor</i>

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.