Toward a Total Synthesis of Macrocyclic Jatrophane Diterpenes - Concise Route to a Highly Functionalized Cyclopentane Key Intermediate
作者:Johann Mulzer、Gerald Giester、Michael Gilbert
DOI:10.1002/hlca.200590124
日期:2005.6
A total synthesis of the biologically potent jatrophane diterpenes pepluanin A (1) and euphosalicin A (2) is being aimed at. En route to these targets, a concise synthesis of the nonracemic cyclopentane building block 74 was developed. Key steps were a Claisen–Eschenmoser rearrangement of the enantiomerically enriched allylic alcohol 14 to amide 34 (Scheme 7), a hydroxy-lactonization of 40 to 43 (Scheme 9)
旨在生物学上有效的麻疯树二萜萜蛋白素A(1)和大磷霉素A(2)的总合成。在达到这些目标的过程中,开发了非外消旋环戊烷结构单元74的简明合成方法。关键步骤是一个克莱森- Eschenmoser对映体富集的烯丙醇的重排14为酰胺34(方案7)中,一个羟基-内酯化40至43(方案9),随后反式-lactonization至72,将其经受戴维斯羟基化至69(方案17)。最终,化合物69被转化为三氟甲磺酸烯醇酯74。这种材料应证明适合于所需的麻疯树1和2的大环特性的环化。由于其固有的有价值的信息内容,因此也讨论了不太成功的方法。