The condensation of 4'-O-(benzyloxycarbonyl)-4'-demethylepipodophyllotoxin (I) with allyltrimethylsilane (II) by means of boron trifluoride ethearate in dichloromethane gives 4beta-allyl-4'-O-(benzyloxycarbonyl)-4'-demethyl-4-desoxypodophyllotoxin (III), which is oxidized with OsO4 and N-methylmorpholine (NMO) in acetone to the substituted acetaldehyde (IV). The reductocondensation of (IV) with N,N,N'-trimethylethylenediamine (V) by means of sodium cyanoborohydride and acetic acid in CHCl3 affords the protected final product (VI), which is finally hydrogenated with H2 over Pd/C in methanol.