Partialsynthese von 4′‐Demethylepipodophyllotoxin. 22. Mitteilung über mitosehemmende Naturstoffe [1]

Abstract
4′‐Demethylepipodophyllotoxin (III) has been synthesized by epimerisation of 4′‐demethylpodophyllotoxin (I) via the corresponding chloride II. An improved method for the preparation of III has been developed by selective ether cleavage of the easily available podophyllotoxin (V) using the bromoderivatives VI and VII as intermediates.