symmetry-based strategy for the synthesis of the zaragozic acids. Two enantioselective dihyroxylations are used to set the absolute stereochemistry of a C-2 symmetric intermediate. A sequence of a furan photo-oxidation followed by a diastereoselective dihydroxylation breaks the symmetry and sets two quaternary stereocenters. Finally, a group selective lactonization is used to protect one of two secondary hydroxyls
报道了一种新颖的,基于对称性的合成zaragozic酸的策略。两个对映选择性二羟基化用于设定C-2对称中间体的绝对立体
化学。
呋喃光氧化的序列,然后进行非对映选择性二羟基化,破坏了对称性并设置了两个四级立体中心。最后,使用基团选择性内酯化来保护两个仲羟基之一。这完成了该中间体的关键的末端分化。还提出了保护基团去除和氧化的方法。