Enantioselective synthesis of β-hydroxy-α-methyl carbonyl compounds by aldol reaction
作者:Akira Ando、Takayuki Shioiri
DOI:10.1016/s0040-4020(01)81078-4
日期:——
The enantioselective aldol reactions of ketone lithium enolates with aldehydes mediated chiral lithium amides were extensively investigated. The chiral amino ethers 4a–4l and diamines 16a,b were prepared from α-amino acids. The reaction conditions and the substituent effects of chiral lithium amides were examined using 4a–4l and 16a,b in the aldol reaction of lithium enolate of 2,2-dimethyl-3-pentanone
广泛研究了酮基烯酸锂与醛介导的手性锂酰胺的对映选择性醛醇缩合反应。手性氨基醚4a - 4l和二胺16a,b是由α-氨基酸制备的。在2,2-二甲基-3-戊酮的烯醇锂(17a)与苯甲醛的醛醇缩合反应中,使用4a – 4l和16a,b检查了手性锂酰胺的反应条件和取代基效果。当使用4b或4c的氨基锂时,18a获得了92–93%的收率和68%的对映体过量。各种酮17a – 17d与醛的反应提供了40–95%的收率和10–77%的对映体过量的β-羟基-α-甲基羰基化合物18a – 18k。对映体过量77%的最佳结果是使用4b的手性锂酰胺在17a与1-萘醛的醛醇缩合反应中实现的。羟醛18i – 18k容易转化为对映体过量40–60%的羧酸衍生物19a – 19c。