PRODUCTION OF ANTHRACYCLINE COMPOUND R20X2

PURPOSE:To readily obtain the titled compound useful as an antitumor and antibiotic substance in high yield, by allowing an anthracycline compound which is a starting material to stand in the coexistence of acetone, DMF and NH4- containing aqueous solution, trialkylamine. CONSTITUTION:An anthracycline compound; R20X3 of formula I or salt thereof is allowed to stand in the coexistence of acetone and/or DMF and ammonium ion-containing aqueous solution and/or trialkylamine, preferably at nearly room temperature so as to convert hydroxycarbonyl group of R20X3 into hydroxyl group thereof and give the aimed compound of formula II. Each of the above- mentioned components is allowed to coexist, e.g. by dissolving R20X3 in the ammonium ion-containing aqueous solution and/or the trialkylamine and adding the acetone and/or DMF to the resultant solution. The above-mentioned reaction is preferably carried out while ventilating to improve the reaction yield.