Formal Synthesis of (−)-Neopeltolide Featuring a Highly Stereoselective Oxocarbenium Formation/Reduction Sequence
作者:Dionicio Martinez-Solorio、Michael P. Jennings
DOI:10.1021/jo100443h
日期:2010.6.18
The formal synthesis of the unnatural (−)-neopeltolide core is discussed in detail. Efficient application of the Evans’ protocol for the synthesis of 1,3-syn-diols via an intramolecular hetero-Michael addition followed by reductive deprotection of the resulting benzylidene acetal allowed for swift access to the δ-lactone. Central to the synthetic approach is a tandem nucleophilic addition−diastereoselective
详细讨论了非天然(-)-neopeltolide核心的形式合成。埃文斯协议的有效应用是通过分子内杂-迈克尔加成反应合成1,3-顺式二醇,然后对所得的亚苄基乙缩醛进行还原性脱保护反应,从而可以快速进入δ-内酯。合成方法的核心是原位生成的氧碳鎓阳离子的串联亲核加成-非对映选择性轴向还原,以组装新pelolidelide核心的β- C-糖苷部分。