Jutta Schulz

Zur struktur des silybins: synthese von unsymmetrisch substituierten 2.3-trans-benzdioxanen

Zusammenfassung The synthesis of model trans -2-aryl-3-hydroxymethyl-1,4-benzdioxanes is described. These substances are very similar in p.m.r. spectra and fragmentation patterns to the aliphatic residue of silybin, dehydrosilybin and their derivatives, thus confirming the presence of a 1,4-benzdioxane ring in these compounds. Neither cis- nor trans-chroman-3,4-diols show any similarity in p.m.r. spectra to silybin or its derivatives, showing the structural proposal incorporating this unit to be untenable.

Notiz zur Absolutkonfiguration des Epoxipiperolids / Note on the Absulute Configuration of Epoxipiperolide

Abstract The epoxide-ring of (+)-5-[trans-(Z)-2,3- epoxy-1-methoxy-propylidene]-4-methoxy- 2(5H)-furanone (1) was opened hydrogenolytically (palladium/charcoal) to (+)-(2S)-5-(2-hydroxy-1-methoxy-3-phenylpropylidene)- 4-methoxy-2(5H)-furanone (2) whose absolute configuration (2S) was determined applying Horeaus method. For the natural product (+)-1 itself follows (2S,3R) Reconfiguration

SYNTHETISCHE UNTERSUCHUNGEN ZUR STRUKTUR VON SILYBIN

Silybin (I) kann zur Verbindung (II) dehydriert werden, aus der die Methyl= ather (IIIa) und (IIIb) zuganglich sind.