The Asymmetric Synthesis of (2R,3R)- and (2R,3S)-3-Methyl-aspartates via an Enantiodiscrimination Strategy
作者:Steven D. Bull、Stephen G. Davies、A. Christopher Garner、Nadeam Mujtaba
DOI:10.1055/s-2001-14596
日期:——
The enolate of (S)-N,N′-bis-(p-methoxybenzyl)-3-iso-propylpiperazine-2,5-dione exhibits high levels of enantiodiscrimination towards racemic 2-bromo-propionate esters of afford adducts containing two new stereogenic centers which may be deprotected to afford (2R,3R)-3-methyl-aspartates or epimerised and then deprotected to afford (2R,3S)-3-methyl-aspartates as single diastereoisomers in high e.e.
(S)-N,N′-双-(对甲氧基苄基)-3-异丙基哌嗪-2,5-二酮的对映体对外消旋的 2-溴丙酸酯具有高度的对映分辨能力,可以得到含有两个新立体中心的加合物,这些加合物可以去保护得到(2R、3R)-3-甲基-天冬氨酸酯,或者先进行二聚化,然后再进行脱保护,得到(2R,3S)-3-甲基-天冬氨酸酯,它们是高对映异构体。e.