A Practical New Chiral Controller for Asymmetric Diels−Alder and Alkylation Reactions
作者:Georgios Sarakinos、E. J. Corey
DOI:10.1021/ol991007s
日期:1999.12.1
prepared from 1,2-epoxycyclohexane by a simple and practical procedure. The acrylate esters of these alcohols undergo BCl3-catalyzed Diels-Alder reactions with a variety of dienes at -78 to -55 degrees C in CH2Cl2 or C7H8 with high dienophile face selectivity (Table 1). The chiral esters so formed are readily cleaved with recovery of the controllers (+)- or (-)-2. Esters of (+)- and (-)-2 can be converted
通过简单实用的方法由1,2-环氧环己烷制备对映体纯的羟基砜(+)-和(-)-2。这些醇的丙烯酸酯在CH2Cl2或C7H8中于-78至-55摄氏度下,具有多种二烯,经BCl3催化的Diels-Alder反应,具有各种不同的二烯,具有高的亲二烯体选择性(表1)。如此形成的手性酯很容易裂解,并得到控制剂(+)-或(-)-2。(+)-和(-)-2的酯可以转化为Z-钾烯醇盐并以高表面选择性被烷基化。