ANTHRACYCLINONE ACETAL DERIVATIVE

NEW MATERIAL:The compound of formula I (R and R are H or alkyl; R and R may together with bonded N form a ring; X and Y are OH or protected OH, X may be H). EXAMPLE:(4'R, 5'R)-(-)-2-2'-methyl-4',5'-bis(pyrrolidine-1-carbonyl)-1',3'-dioxolan-2'- yl-5,12-dihydroxy-3,4-dihydronaphthacene-6,11-dione. USE:An intermediate for stereospecifically and easily producing an optically active (R)-7-deoxy(or 7,11-dideoxy)-4-demethoxydaunomycin (an intermediate for artificial carcinostatic agent superior to natural agent). Some of the above daunomycin derivatives are novel. PREPARATION:The compound of formula I can be produced by reacting the compound of formula V with the compound of formula VI (R is alkyl) in the presence of an acid catalyst and subjecting the resultant compound of formula VII to acetal exchange reaction with the compound of formula VIII in the presence of an acid catalyst.