[4 + 3] Cycloaddition of Aromatic α,β-Unsaturated Aldehydes and Ketones with Epoxides: One-Step Approach to Synthesize Seven-Membered Oxacycles Catalyzed by Lewis Acid
作者:Yu-Qiang Zhou、Nai-Xing Wang、Shu-Bao Zhou、Zhong Huang、Linghua Cao
DOI:10.1021/jo101669t
日期:2011.1.21
A novel intermolecular [4 + 3] cycloaddition method to construct 1,4-dioxide seven-membered oxacycles was developed. This one-step method was carried out in the presence of catalytic amount of (C2H5)2OBF3 under mild conditions. Seven-membered oxacycles and some natural compounds could be easily synthesized via this protocol. Control experiments were carried out and possible mechanism for the reaction
开发了一种新型的分子间[4 + 3]环加成方法,以构建1,4-二氧化物七元氧杂环。在温和条件下,在催化量的(C 2 H 5)2 OBF 3存在下进行该一步方法。通过此协议,可以轻松合成七元氧杂环和一些天然化合物。进行了对照实验,并提出了可能的反应机理。进行不对称反应,得到具有中等ee值的3e。