丁氨二酰

Started from D-tyrosine, we obtained the tetramic acid 96 using Jouin reaction. The assembly of the second fragment 109 was stared from 1,4-butandiol,using asymmetric alkylation reaction developed by Oppolzer as a key step. Coupling of the tetramic acid 96 with 109 provided the key intermediate 110 according to Yoshii\'s procedure. After remove protective group and Sharpless epoxidation, we obtained the key intermediate 113. Its macrocyclization to form the final product is in progress.

本论文的第二章主要对Macrocidin A开展了合成工作，我们从D构型的酪氨酸出发，经过官能团转换；利用Jouin反应生成Tetramic acid 96，另外一个片断从1，4-丁二醇开始经过多步反应生成碘化物104，利用Oppolzer发展的手性樟脑磺酰胺为辅基参与的不对称烷基化反应，引入手性甲基，生成关键中间体109，接着通过Yoshii发展的方法连接96和109生成110，经过Sharpless不对称环氧化反应建立环氧化合物，然后脱去保护基得到关环前体113，分子内的Mitsunobu反应进行关大环反应正在进行之中。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。