R-Amino acid esters 1, 2 and 3 are novel compounds possessing hypnotic activity. On attempting an asymmetric synthesis of these molecules, racemisation was observed when reacting bis(2-methoxyethyl)amine with α-bromo intermediate 4. In vitro plasma stability studies showed that the R enantiomers had much greater resistance to esterase-mediated degradation than the corresponding S enantiomers. This observation led to the use of commercially available pig liver esterase to prepare 1, 2 and 3 on a multigram scale. The crystal structures of 1 and 2 are reported and confirm R configuration.
R-
氨基酸酯 1、2 和 3 是具有催眠活性的新型化合物。在尝试不对称合成这些分子时,当双(2-甲氧基乙基)胺与δ-
溴中间体 4 反应时,观察到了外消旋化现象。体外血浆稳定性研究表明,与相应的 S 对映体相比,R 对映体对
酯酶介导的降解具有更强的抵抗力。根据这一观察结果,我们使用市售的猪肝
酯酶制备了多克规模的 1、2 和 3。报告了 1 和 2 的晶体结构,并确认了 R 构型。