描述了 callipeltoside A 的对映选择性全合成。包括大环内酯亚基的两种合成:第一种依赖于爱尔兰-克莱森重排来产生三取代的烯烃几何结构,第二种利用对映选择性插烯羟醛反应来实现此目的。还公开了糖和氯代环丙烷侧链片段的对映选择性合成。该天然产物的相对和绝对立体化学通过与侧链片段的两种对映异构体的片段偶联来确定。
Asymmetric Synthesis of the Chlorocyclopropane-Containing Callipeltoside A Side Chain
摘要:
[GRAPHICS]The callipeltoside A chlorocyclopropyl-containing dienyne side chain has been synthesized in nine steps and 33% overall yield from commercially available 1,2,5,6-O-dicyclohexylidene-D-mannitol. The key steps in the synthesis are a highly diastereoselective cyclopropanation of a vinyl chloride allylic ether and a Suzuki cross-coupling to complete the carbon framework.