The total synthesis of zaragozic acid C has been achieved by a convergent strategy, wherein the key feature of the construction of 2,8-dioxabicyclo[3.2.1]octane core structure is a simultaneous creation of the C4 and C5 quaternary carbon centers by Sn(OTf)2-promoted aldol coupling reaction between α-keto ester and silyl ketene thioacetal derived from L- and D-tartaric acids, respectively.
2,8-dioxabicyclo[3.2.1]octane 核心结构的主要特征是通过 Sn(OTf)2 促进的δ-
酮酯与
硅酮
硫代
乙醛的醛醇偶联反应同时生成 C4 和 C5 季碳中心。