Absolute stereochemistries and total synthesis of (+)-arisugacins A and B, potent, orally bioactive and selective inhibitors of acetylcholinesterase
作者:Toshiaki Sunazuka、Masaki Handa、Kenichiro Nagai、Tatsuya Shirahata、Yoshihiro Harigaya、Kazuhiko Otoguro、Isao Kuwajima、Satoshi Ōmura
DOI:10.1016/j.tet.2004.06.059
日期:2004.8
of a 4-hydroxy-2-pyrone derivative as a key reaction; and (iii) stereoselective dihydroxylation to give the diol derivative, followed by deoxygenation. Accordingly, we defined the absolute structures of arisugacins A and B as 4a-(R),6a-(R),12a-(R), and 12b-(S). Finally, we characterized the bioactivities of the synthetic intermediates to understand the structure–activity relationships of the arisugacins
在当前的研究中,我们使用了Mosher NMR方法的Kakisawa–Kashman修饰法来确定Arisugacins的完全绝对立体化学。我们还报告了由(i)钌络合物催化的环己烯酮衍生物的不对称还原引起的(+)-芦荟素A和B的聚合全合成。(ii)通过α,β-不饱和醛衍生物的Knoevenagel型反应,以4-羟基-2-吡喃酮衍生物的产生为关键反应,来立体选择性地构建阿瑞新霉素骨架;(iii)立体选择性二羟基化得到二醇衍生物,然后脱氧。因此,我们将阿瑞沙星A和B的绝对结构定义为4a-(R),6a-(R),12a-(R)和12b-(S)。最后,我们对合成中间体的生物活性进行了表征,以了解arisugacins的结构-活性关系。