| 摘要 |
<p>A process for the preparation of antibiotics of the anthracycline class of formula (A), wherein R1 is hydrogen, OH, or OCOR2, wherein R2 is a C1-C4-alkyl group; which comprises the epimerization of the 4' hydroxy group of the daunosamine residue by nucleophilic substitution of a triflate group with a carboxylate, which epimerization is carried out on the whole molecule with the hydroxy groups being protected, and subsequent transformation into the final product.</p> |
