| 18656980 |
Feng JP, Shi ZF, Li Y, Zhang JT, Qi XL, Chen J, Cao XP: An improved asymmetric synthesis of malyngamide U and its 2'-epimer. J Org Chem. 2008 Sep 5;73(17):6873-6. 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. |
33(0,1,1,3) |