An efficient, regiospecific synthesis of 4-demethoxydaunomycinone and daunomycinone

YASUMITSU TAMURA, MANABU SASHO, SHUJI AKAI, HISAKAZU KISHIMOTO, JUN-ICHI SEKIHACHI, YASUYUKI KITA
1987 Chemical and pharmaceutical bulletin  
4-Methoxy and 4-acetoxyhomophthalic anhydrides were prepared by convenient oxidations of homophthalic acid derivatives followed by hydrolysis and dehydrative cyclization. Strong baseinduced cycloaddition of these anhydrides to 2-ehloro-6,6-ethylenedioxy-5,6,7,8-tetrahydro-1,4naphthoquinone gave the tetracyclic adducts, which were efficiently converted into 4-demethoxydaunomycinone and daunomycinone.
doi:10.1248/cpb.35.1405 fatcat:adysnelvjzcxbdcrt3icsbjkuy