Total Synthesis of (−)-Denticulatins A and B Using Efficient Methods of Acyclic Stereocontrol.
作者:Ian Paterson、Michael V. Perkins
DOI:10.1016/0040-4020(95)01015-7
日期:1996.1
The total synthesis of (−)-denticulatin B (2) was achieved in 9 steps (20% yield), with 70% overall diastereoselectivity, starting from the ethyl ketone (R)-9. Most of the stereochemistry was introduced by substratebased control. Key steps include the boron-mediated aldol/reduction, 9 → 22, the titanium-mediated aldol coupling, 26 + 8 → 38, and the directed cyclisation, 35 → 2. Epimerisation at C10
(-)-denticulatin B(2)的总合成从乙基酮(R)-9开始,分9步完成(20%的收率),总非对映选择性为70%。大部分立体化学是通过基于底物的控制引入的。关键步骤包括硼介导的羟醛/还原9→22,钛介导的羟醛偶联26 + 8→38和定向环化35→2。35中C 10的差向异构化导致(-)-denticulatin A(1)。