作者:Yves Bousquet、Paul C. Anderson、Tibor Bogri、Jean-Simon Duceppe、Louis Grenier、Ingrid Guse
DOI:10.1016/s0040-4020(97)10059-x
日期:1997.11
Two approaches to enantiopure 4-oxo- and 4-(R)-hydroxypipecolic acid derivatives from protected L-aspartic acid were developed. The first route exploits an intramolecular Michael addition on the stable enaminone 8. Hydrogenation and concomitant decarboxylation gave the 4-oxo derivative 11 which was reduced selectively to the 4-(R)-hydroxy derivative 12. The second route starts with a Michael addition
开发了两种从受保护的L-天冬氨酸中提取对映体纯的4-氧代和4-(R)-羟基哌酸衍生物的方法。第一条途径是在稳定的烯胺酮8上使用分子内迈克尔加成法。氢化和伴随的脱羧得到4-氧代衍生物11,其选择性地还原成4-(R)-羟基衍生物12。第二种途径是从迈克尔加成反应开始,然后进行分子内狄克曼缩合以建立哌啶环。4-氧代衍生物11和19因此,无需任何色谱纯化就可以快速,大规模地获得氨基甲酸酯。两种序列均被证明是高度立体选择性的。