Improved and Practical Procedures for the Preparation of Highly Substituted Pyridines and Pyridazines via Silica-Mediated Aromatisation
作者:Richard Taylor、Nicola Catozzi、William Bromley、Pierre Wasnaire、Mairi Gibson
DOI:10.1055/s-2007-984918
日期:——
A new and straightforward procedure is described for the preparation of highly substituted pyridines and pyridazines. The method involves a Diels-Alder/retro-Diels-Alder sequence leading to dihydropyridine or related intermediates, which can be aromatized to pyridines and pyridazines by treatment with silica gel. The value of this procedure has been demonstrated with a one-step -synthesis of an E-ring-modified
描述了一种新的、直接的方法来制备高度取代的吡啶和哒嗪。该方法涉及 Diels-Alder/retro-Diels-Alder 序列,导致二氢吡啶或相关中间体,可以通过硅胶处理将其芳构化为吡啶和哒嗪。该程序的价值已通过 E 环修饰的类固醇的一步合成得到证明。