Aitken R Alan, Harper Andrew D, Slawin Alexandra M Z
EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, Fife, UK.
Molecules. 2021 Dec 20;26(24):7690. doi: 10.3390/molecules26247690.
Three isomeric (benzyloxythienyl)oxazolines , and have been prepared and are found, upon treatment with a strong base, to undergo either Wittig rearrangement or intramolecular attack of the benzylic anion on the oxazoline function to give products derived from cleavage of the initially formed 3-aminothienofuran products. This pattern of reactivity is directly linked to the distance between the two reactive groups as determined by X-ray diffraction, with the greatest distance in leading to exclusive Wittig rearrangement, the shortest distance in giving exclusively cyclisation-derived products, and the intermediate distance in leading to both processes being observed. The corresponding -butyl amides were also obtained in two cases and one of these undergoes efficient Wittig rearrangement leading to a thieno[2,3-]pyrrolone product.
已制备出三种异构的（苄氧基噻吩基）恶唑啉，即 和 ，并且发现，在用强碱处理时，它们会发生维蒂希重排或苄基阴离子对恶唑啉官能团的分子内进攻，从而得到由最初形成的3-氨基噻吩并呋喃产物裂解衍生而来的产物。这种反应模式与通过X射线衍射确定的两个反应基团之间的距离直接相关， 中两个反应基团之间的距离最大，导致仅发生维蒂希重排； 中距离最短，仅生成环化衍生产物； 中的中间距离则导致两种过程都被观察到。在两种情况下还得到了相应的丁基酰胺，其中一种经历了有效的维蒂希重排，生成了噻吩并[2,3-]吡咯酮产物。
