Total syntheses of cepaciamides A and B were accomplished. In the preparation of two fatty acid segments, (S)-malic acid was used as a chiral source to introduce (2S)-configuration. A known chiral cyclopropane derivative was introduced in the segment of cepaciamide A. The formation of (Z)-olefin in the segment of cepaciamide B was achieved by means of partial reduction of the acetylenic bond. Esterification
完成了头孢西酰胺A和B的全部合成。在两个
脂肪酸片段的制备中,(S)-
苹果酸被用作手性来源以引入(2S)-构型。将已知的手性
环丙烷衍
生物引入到西ci酰胺A的链段中。通过部分还原炔键,在西epa酰胺B的链段中形成(Z)-烯烃。用
DCC /
DMAP酯化
脂肪酸链段和酰胺链段,然后用CAN对MPM基团进行氧化脱保护,得到西帕西酰胺。