Feng Jian-Peng, Shi Zi-Fa, Li Yang, Zhang Jun-Tao, Qi Xian-Liang, Chen Jie, Cao Xiao-Ping
State Key Laboratory of Applied Organic Chemistry and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, PR China.
J Org Chem. 2008 Sep 5;73(17):6873-6. doi: 10.1021/jo800876u. Epub 2008 Jul 26.
An accelerated and improved asymmetric synthesis of malyngamide U (1) and its 2'-epimer (2'-epi-1) was accomplished from readily available n-hexanal, ethanolamine and (R)-(-)-carvone. The key steps involved a Johnson-Claisen rearrangement in the synthesis of an unsaturated carboxylic acid 4 and an aldol reaction in the construction of the skeleton of 1 and 2'-epi-1. There are 13 steps in the synthesis, with a 2.7% overall yield for 1 and a 0.4% yield for 2'-epi-1.
以易得的正己醛、乙醇胺和(R)-(-)-香芹酮为原料，实现了马蔺酰胺U（1）及其2'-差向异构体（2'-epi-1）的加速且改进的不对称合成。关键步骤包括在不饱和羧酸4的合成中进行的约翰逊-克莱森重排，以及在1和2'-epi-1骨架构建中进行的羟醛反应。该合成共有13步，1的总收率为2.7%，2'-epi-1的收率为0.4%。
