synthesized. Oxidative ring‐opening of a furan unveils an amine‐tethered dicarbonyl, which undergoes spontaneous transannular Mannich cyclization. The cascade builds the full cephalotaxine substructure in a single operation in 60 % yield. A Noyori reduction enabled synthesis of the title compounds with excellent enantioselectivity (krel=278).
                                    合成了人harringtonine及其同类物头孢他辛。
呋喃的氧化性开环揭示了一种胺系的二羰基化合物,该胺基化合物会自发地经过环面Mannich环化。级联通过一次操作以60%的产率构建完整的头孢他辛亚结构。通过Noyori还原,能够以优异的对映选择性(k rel= 278)合成标题化合物。