Takahashi Shunya, Hongo Yayoi, Ogawa Narihito, Koshino Hiroyuki, Nakata Tadashi
RIKEN (The Institute of Physical and Chemical Research), Wako-shi, Saitama, 351-0198, Japan.
J Org Chem. 2006 Aug 4;71(16):6305-8. doi: 10.1021/jo060970q.
This paper describes a second-generation synthesis of an antitumor tetrahydropyran (THP) acetogenin, pyragonicin. The key step involved an olefin cross-metathesis between the THP segment and the terminal gamma-lactone residue. The coupling reaction in the presence of Grubbs' second-generation catalyst resulted in an unseparable mixture of a desired coupling product and its one-carbon eliminated product while the use of Grubbs' first-generation catalyst afforded the former exclusively. A novel MOM-migrating reaction found in a cyclization reaction is also discussed.
本文描述了抗肿瘤四氢吡喃（THP）产乙酸素——派罗尼辛的第二代合成方法。关键步骤涉及THP片段与末端γ-内酯残基之间的烯烃交叉复分解反应。在格拉布第二代催化剂存在下的偶联反应产生了所需偶联产物及其单碳消除产物的不可分离混合物，而使用格拉布第一代催化剂则仅得到前者。还讨论了在环化反应中发现的一种新型甲氧基甲基迁移反应。
