synthesized. NMR analogies show that kodaistatin A must be trans‐configured. A key‐step was a syn‐selective aldol addition. An oxidation/reduction tandem furnished the β‐epimeric anti‐aldol. Each aldol was processed to a 5‐brominated 1,4‐diketone. The latter cyclized by an SmI2‐mediated aldol addition. Ensuing dehydrations delivered the cyclopentenone motive.
合成了柯达他汀AD的二羟基
环戊烯酮核心的顺式/反式异构体模型。NMR类比表明,必须对kodaistatin A进行反式配置。关键步骤是添加顺式选择性羟醛。氧化/还原串联提供了β-表异构体抗-羟醛。每个羟醛都被加工成5
溴1,4-二酮。后者通过SmI 2介导的羟醛加成而环化。随后的脱
水传递了
环戊烯酮的动机。