An Asymmetric Aldol−Ring-Closing Metathesis Strategy for the Enantioselective Construction of Oxygen Heterocycles: An Efficient Approach to the Enantioselective Synthesis of (+)-Laurencin
作者:Michael T. Crimmins、Allison L. Choy
DOI:10.1021/ja990421k
日期:1999.6.1
A strategy is described for the enantioselective construction of medium-ring cyclic ethers by merging the asymmetric aldol addition of glycolates with a ring-closing metathesis reaction. Cyclic ethers of seven-, eight-, and nine-membered rings are readily available through a ring-closing metathesis without cyclic conformational constraints, by exploiting the acyclic conformational bias of the gauche
通过将乙醇酸酯的不对称羟醛加成与闭环复分解反应相结合,描述了一种对映选择性构建中环环醚的策略。通过利用 gauche 效应的非环状构象偏差,七元、八元和九元环的环醚很容易通过闭环复分解获得,而没有环状构象限制。已经利用醛醇-复分解组合完成了八元醚 (+)-月桂酸红藻代谢物的简短正式合成。