Stereoselective 1,3-dipolar cycloadditions of nitrones derived from amino acids. Asymmetric synthesis of N-(alkoxycarbonylmethyl)-3-hydroxypyrrolidin-2-ones
作者:Pedro Merino、Graziella Greco、Tomás Tejero、Ramon Hurtado-Guerrero、Rosa Matute、Ugo Chiacchio、Antonino Corsaro、Venerando Pistarà、Roberto Romeo
DOI:10.1016/j.tet.2013.08.084
日期:2013.11
Diastereoselective asymmetric 1,3-dipolar cycloadditions of N-(alkoxycarbonylmethyl) nitrones derived from glycine, alanine and phenylalanine have been studied both experimentally and theoretically. Asymmetric induction is evaluated by either introducing a chiral group at the nitrone nitrogen atom or by using Oppolzer's sultam acrylamide. In both cases the sense of the asymmetric induction is the same
非对映选择性的不对称1,3-偶极环加成ñ -选自甘氨酸,丙氨酸和苯丙氨酸衍生的(烷氧羰基)硝酮进行了实验和理论研究两者。不对称诱导通过在硝酮氮原子无论是引入手性基团,或通过使用将Oppolzer的磺内酰胺的丙烯酰胺进行评价。在两种情况下,不对称诱导的意义上是相同的,所述(3 - [R,5 - [R )-异构体被优先获得。用手性双极性亲和剂观察到最好的结果,在所有情况下都提供唯一的异构体。将获得的异恶唑烷易于转化为相应的5-取代的3-羟基-2-酮。DFT研究是与观察到的实验结果定性一致。