Method of preparation of the 4 ′ - demethylepipodophyllotoxin on the basis of podophyllotoxin

摘要

A method for synthesising a 4'-demethylepipodophyllotoxin of formula (II) from a podophyllotoxin of formula (I) by treating it with a pair of reagents, i.e. a strong acid and an aliphatic, aromatic or functionalised sulphide, in the presence of an organic or inorganic acid, or in the presence of water with or without a water-miscible organic solvent.