作者:Valentina Favero、Gianni Porzi、Sergio Sandri
DOI:10.1016/s0957-4166(97)00013-x
日期:1997.2
The alkylation of 7 occurs in moderate to good trans stereoselection (d.e.40–98%), while a poorer d.e. (10–90%) is observed for 8. On the contrary, in both substrates the alkylation with CH3I produces a greater amount of the cis isomer (d.e48%). Cleavage of the lactims 9(a,e) gives enantiomerically pure dipeptides 14(a,e). The absolute configuration of the introduced stereogenic centres has been assigned
的烷基化7发生在中度至良好的反式,而较差的德(10-90%)可以观察到立体选择性(de40-98%),8。相反,在两种底物中,用CH 3 I烷基化都会产生大量的顺式异构体(d.e48%)。内酰胺9(a,e)的切割产生对映体纯的二肽14(a,e)。引入的立体异构中心的绝对构型已基于与构象分析相关的1 H-NMR数据进行了分配。