Preparation of 4-demethoxy-daunomycinone, the aglycone of 4-demethoxy-daunorubicin

摘要

4-Demethoxy-daunomycinone I: CHEM the known aglycone of 4-demethoxy-daunorubicin, is prepared by protecting the 13-keto group of 4-demethyl-daunomycinone, sulfonylating the 4-hydroxy group, reacting the sulfonylated compound with an amine, removing the amino protecting group from the resultant 4-demethyl-4-(protected amino)-13-dioxolanyl-daunomycinone, diazotising the thus-freed 4-amino group and reducing under mild conditions the resulting diazonium compound.