Highly Diastereofacial <i>Anti</i>-Aldol Reaction: Practical Synthesis of Optically Active <i>anti</i>-2-Alkyl-3-Hydroxycarboxylic Acid Ester Units
作者:Michio Kurosu、Miguel Lorca
DOI:10.1021/jo001293h
日期:2001.2.1
variety of esters derived from commercially available norephedrine were used in diastereoselective anti-aldol reactions. The aldol reaction of designed 2-(N-2-methylbenzyl-N-2,4,6-trimethylbenzyl)amino-1-phenylpropanol esters 4a-d with aldehydes furnished anti-2-alkyl-3-hydroxycarboxylic acid esters in excellent diastereomeric ratios (>98:2) when LDA-Cp2ZrCl2 (0.3 equiv) was used for enolization, followed
在非对映选择性抗醛醇缩合反应中使用了多种从市售的去甲麻黄碱衍生的酯。设计的2-(N-2-甲基苄基-N-2,4,6-三甲基苄基)氨基-1-苯基丙醇酯4a-d与醛的醛醇缩合反应生成了出色的非对映异构体的抗-2-烷基-3-羟基羧酸酯当使用LDA-Cp2ZrCl2(0.3当量)进行烯化时,比率为(> 98:2),然后将金属转移成烯醇化锆进行醛醇缩合。用于抗醛醇缩合反应的新型助剂3不具有叔胺的普通碱性。3可以用有机溶剂从酸性介质中提取。因此,它的使用不仅对于从酸性水溶液中提取醛醇类产物,而且对于在还原裂解后回收手性助剂3都是非常有利的。