Concerning Synthesis of Ring-A Fluorinated Anthracyclines. The Dioxirane Shunt.

In a key step of the synthesis of 8-fluoroanthracycline aglycons, epoxidn. of the electron-poor C8-C9 double bond moiety presented by the 8-acetyl-6,11-dimethoxy-7,10-dihydronaphthacene-5,12-dione starting material can be achieved in high yield and case of operations using methyl(trifluoromethyl)dioxirane.