The ketalization of daunorubicin (I) in the usual way gives daunorubicin-13-dimethylketal (II), which is brominated to 14-bromodaunorubicin-13-dimethylketal (III). The hydrolysis of (III) yields 14-bromodaunorubicin (IV), which is finally treated with sodium diethoxyacetate in refluxing acetone. The title product can also be obtained by reaction of (III) with sodium diethoxyacetate (A) in the same way.