Mukai Ken, Kasuya Satoshi, Nakagawa Yuki, Urabe Daisuke, Inoue Masayuki
Graduate School of Pharmaceutical Sciences , The University of Tokyo , Hongo , Bunkyo-ku , Tokyo 113-0033 , Japan . Email:
Chem Sci. 2015 Jun 1;6(6):3383-3387. doi: 10.1039/c5sc00212e. Epub 2015 Mar 30.
A convergent total synthesis of ouabagenin, an aglycon of cardenolide glycoside ouabain, was achieved by assembly of the AB-ring, D-ring and butenolide moieties. The multiply oxygenated -decalin structure of the AB-ring was constructed from ()-perillaldehyde through the Diels-Alder reaction and sequential oxidations. The intermolecular acetal formation of the AB-ring and D-ring fragments, and combination of the intramolecular radical and aldol reactions, assembled the requisite steroidal skeleton in a stereoselective fashion. Finally, stereoselective installation of the C17-butenolide the Stille coupling and hydrogenation led to ouabagenin.
通过组装A/B环、D环和丁烯内酯部分，实现了强心甾糖苷哇巴因的苷元哇巴因苷元的汇聚式全合成。A/B环的多氧代十氢萘结构由（）-紫苏醛通过狄尔斯-阿尔德反应和连续氧化构建而成。A/B环和D环片段的分子间缩醛形成，以及分子内自由基反应和羟醛反应的结合，以立体选择性方式组装了所需的甾体骨架。最后，通过施蒂勒偶联和氢化反应立体选择性地安装C17-丁烯内酯，得到哇巴因苷元。
