ChemInform Abstract: A SIMPLE AND EFFICIENT SYNTHESIS OF KEY SYNTHETIC INTERMEDIATES OF 4-DEMETHOXYANTHRACYCLINONES, (.+-.)- AND (R)-(-)-7-DEOXY-4-DEMETHOXYDAUNOMYCINONE

(±)-2,5,12-Trihydroxy-1,2,3,4-tetrahydronaphthacene-6,11-dione-2-carboxylic acid was found to readily afford the racemic title compound by successive treatments with N,N′-carbonyldiimidazole and methylmagnesium bromide in the presence of trimethylsilyl triflate. The same reaction scheme could also furnish the optically pure title compound from the (R)-carboxylic acid produced by the optical resolution.