4-Methoxy and 4-acetoxyhomophthalic anhydrides were prepared by convenient oxidations of homophthalic acid derivatives followed by hydrolysis and dehydrative cyclization. Strong base-induced cycloaddition of these anhydrides to 2-ehloro-6, 6-ethylenedioxy-5, 6, 7, 8-tetrahydro-1, 4-naphthoquinone gave the tetracyclic adducts, which were efficiently converted into 4-demethoxydaunomycinone and daunomycinone.
通过均苯二
甲酸衍
生物的简便氧化法制备了 4-甲氧基和 4-乙酰氧基均苯二
甲酸酐,然后进行了
水解和脱
水环化。在强碱诱导下,这些酸酐与 2-
氯-6, 6-亚乙二氧基-5, 6, 7, 8-四氢-1, 4-
萘醌发生环加成反应,生成四环加合物,并有效地转化为 4-去甲氧基大诺霉素酮和大诺霉素酮。