Structure Assignment of Lagunapyrone B by Fluorous Mixture Synthesis of Four Candidate Stereoisomers
作者:Fanglong Yang、Jeffery J. Newsome、Dennis P. Curran
DOI:10.1021/ja064812s
日期:2006.11.1
Techniques of fluorous mixture synthesis have been used to make four candidate stereoisomers for the natural product lagunapyrone B. A quasiracemic mixture of vinyl iodides whose component configurations at C19-21 were encoded by fluorous silyl groups was fused to a central fragment by a Negishi coupling. A separate quasiracemic mixture of pyrone fragments whose component configurations at C6,7 were
含氟混合物合成技术已用于制备天然产物拉格纳派隆 B 的四种候选立体异构体。其 C19-21 的组分构型由含氟甲硅烷基编码的乙烯基碘类准外消旋混合物通过 Negishi 偶联与中心片段融合。合成并分层了单独的吡喃酮片段的准外消旋混合物,其 C6,7 处的组分配置也由含氟甲硅烷基编码。所得纯准对映异构体与准外消旋混合物的Stille偶联提供两个准非对映异构体样品,将其分层并去标签以提供所有四种lagunapyrone B立体异构体。通过旋光度比较,Lagunapyrone 被指定为 6R、7S、19S、20S、21R 构型。