合成路线1

The reaction of daunomycinone (IX) with AlCl3 in dichloromethane gives 4-demethyldaunomycinone (X), which is ketalized with ethylene glycol as before yielding the dioxolane (XI). The selective sulfonation of (XI) with TsCl, DIEA and DMAP in pyridine affords the 4-tosyloxy derivative (XII), which is treated with 4-methoxybenzylamine (XIII) in pyridine providing the secondary benzylamine (XIV). Elimination of the benzyl protecting group of (XIV) with TFA gives 4-amino-4-demethoxydaunomycinone ethylene ketal (XV), which is deaminated by reaction with TFA, NaNO2 and H3PO2 to give 4-demethoxydaunomycinone (XVI). Finally, this compound is submitted to fermentation with Streptomyces peucetius corneus, S. Peucetius caesius, S. Caeruleus, S. Peucetius, S. Coeruleorubidus, and other chemical or radio-induced mutants thereof.