The Dimroth rearrangement as a probable cause for structural misassignments in imidazo[1,2-a]pyrimidines: A N-labelling study and an easy method for the determination of regiochemistry
作者:Maria Chatzopoulou、R. Fernando Martínez、Nicky J. Willis、Timothy D.W. Claridge、Francis X. Wilson、Graham M. Wynne、Stephen G. Davies、Angela J. Russell
DOI:10.1016/j.tet.2018.06.033
日期:2018.9
Structural misassignments are often seen for complex natural products, but this can also be an issue with seemingly simpler structures. In this paper, we describe how, using a 15N-labelled analogue, we established that the Dimroth rearrangement can occur in imidazo[1,2-a]pyrimidines and result in an incorrect regiochemical assignment of such compounds. These studies supported a rearrangement mechanism
对于复杂的天然产品,经常会出现结构上的错误分配,但这对于看似简单的结构也可能是一个问题。在本文中,我们描述了如何使用15 N标记的类似物确定Dimroth重排可发生在咪唑并[1,2- a ]嘧啶中并导致此类化合物的区域化学错误分配。这些研究支持了包括添加氢氧离子然后开环的重排机制。还观察到,可以使用1 H NMR光谱轻松地区分C(2)和C(3)取代的区域异构体。