作者:Eric McClendon、Ann O. Omollo、Edward J. Valente、Ashton T. Hamme II
DOI:10.1016/j.tetlet.2008.11.053
日期:2009.2
The stereoselective synthesis of 4-bromo-spiro-isoxazolines was achieved in one step through the bromination of various isoxazoles that contain a pendant alcohol or carboxylic acid functional group. Isoxazole bromination leads to a bromonium ion intermediate, which opens either by neighboring oxygen lone pair electrons or by intramolecular nucleophilic attack. Single X-ray crystal data provide evidence
4-溴-螺-异恶唑啉的立体选择性合成是通过对含有侧醇或羧酸官能团的各种异恶唑进行溴化而一步完成的。异恶唑溴化产生溴离子中间体,它通过相邻的氧孤对电子或分子内亲核攻击打开。单个 X 射线晶体数据提供证据表明,螺环异恶唑啉的两个连续立体中心是由亲核试剂相对于溴的反分子内攻击形成的,因为螺环氧和溴原子之间存在反立体化学关系。