The synthesis of epsilon-rhodomycinone- and carminomycin-11-methyl ethers

The conversion of epsilon-rhodomycinone to its 11-methyl ether via selective hydrolysis of the 4,6,7,11-tetraacetate is described. This series of reactions was used as a model for the conversion of carminomycin to its 11-methyl ether. The anti-tumor activity of the latter compound was less than that of both carminomycin and its 4-methyl ether (daunomycin).