Synthetic study of kosinostatin aglycone: synthesis of BCDE rings using alkoxycarbonylmethylation of diazonaphthoquinone
作者:Mitsuru Kitamura、Kenji Kubo、Shogo Yoshinaga、Hiroki Matsuzaki、Kantaro Ezaki、Taisuke Matsuura、Daigo Matsuura、Noriyuki Fukuzumi、Keiichiro Araki、Masafumi Narasaki
DOI:10.1016/j.tetlet.2014.01.082
日期:2014.2
A synthetic study of kosinostatin aglycone is reported. Synthesis of key intermediate lactone 3, which corresponds to the BCDE ring fragment, was accomplished, and the precursor BCD ring fragment 5 was synthesized via two routes. First, 5 was synthesized from 2,5-dimethoxybenzaldehyde 16 by the combination of typical known transformations including efficient application of non-aqueous OsO4 oxidation
据报道对kosinostatin糖苷配基的合成研究。完成了对应于BCDE环片段的关键中间体内酯3的合成,并通过两种途径合成了前体BCD环片段5。首先,通过2,5-二甲氧基苯甲醛16的合成,包括典型的已知转化,包括在PhB(OH)2存在下有效应用非水OsO 4氧化,合成5。但是,合成需要15个漫长的步骤,其主要困难是邻位1-萘酚的-烷氧基羰基甲基化。接下来,我们尝试将我们最近开发的重氮萘醌的烷氧基羰基甲基化用于5的合成,并且5是在9个步骤中从相同的起始化合物16成功合成的。最后,经由三氟乙酸介导的3,4-环氧环己烷羧酸衍生物的环化,将5立体选择性地转化为内酯3。