The phenanthrenone
(6) was converted into 1H-2,10a-ethanophenanthrene (16) by means of an acid-induced
cyclization of α-diazoketone (14). Protection
and hydrogenation of (16), followed by reductive methylation of the resulting
tetracyclic ester (20) gave the corresponding dihydro
derivatives(22) or (23), potential precursors to gibberellic
acid (8).
菲酮
(6)通过酸诱导的α-二氮酮(14)环化反应转化为 1H-2,10a-乙烷菲(16)。
α-重氮酮(14)的环化作用,转化成 1H-2,10a-乙酮蒽(16)。保护
保护和氢化 (16),然后对生成的四环酯进行还原甲基化
(16)的保护和氢化,然后将得到的四环酯(20)还原甲基化,得到相应的二氢
衍生物(22)或(23),它们是赤霉素(8)的潜在前体。
酸 (8) 的潜在前体。