Chemistry of renieramycins. Part 12: An improved total synthesis of (±)-renieramycin G
作者:Masashi Yokoya、Kimiko Shinada-Fujino、Saiko Yoshida、Masahiro Mimura、Hiroki Takada、Naoki Saito
DOI:10.1016/j.tet.2012.03.105
日期:2012.6
An improved total synthesis of (±)-renieramycin G (1g) from readily available 2-hydroxy-3-methyl-4,5-dimethoxybenzaldehyde (7) in 21 steps (6.3% overall yield) is described. The synthesis features the concise construction of a pentacyclic framework using the stereoselective Pictet–Spengler type cyclization reaction of lactam (25) with ethyl diethoxyacetate, followed by the base-catalyzed epimerization
从21步(6.3%的总收率)描述了一种由易于获得的2-羟基-3-甲基-4,5-二甲氧基苯甲醛(7)改进的(±)-雷尼霉素G(1g)的总合成的方法。合成的特征是使用内酰胺(25)与二乙氧基乙酸乙酯的立体选择性Pictet-Spengler型环化反应,然后用碱催化醛的C-1立体中心的差向异构化(30a),简化五环骨架的构建。还介绍了细胞毒性研究的结果。