A retro Diels–Alder method for the preparation of pyrrolo[1,2-a]pyrimidinediones from diexo-aminooxanorbornenecarboxamide
作者:Géza Stájer、Angela E. Szabó、Pál Sohár、Antal Csámpai、Reijo Sillanpää
DOI:10.1016/j.molstruc.2005.09.011
日期:2006.2
with the oxocarboxylic acids: 4-oxopentanoic acid, p-chlorobenzoylpropionic acid or 2-formylbenzoic acid, the pyrrolo[1,2-a]pyrimidinediones 2 and 3 or pyrimido[1,2-a]isoindoledione 4 were formed on cyclization and thermolysis, when the parent cycles decomposed via the loss of furan to give 2–4 in a retro Diels–Alder reaction. With cis-or trans-2-aroylcyclohexanecarboxylic acids as starting compounds
摘要 通过 diexo-3-amino-7-oxanorbornene-2-carboxamide 1 与氧代羧酸:4-氧代戊酸、对氯苯甲酰基丙酸或 2-甲酰基苯甲酸的反应,吡咯并[1,2-a]嘧啶二酮 2和 3 或嘧啶并[1,2-a]异吲哚二酮 4 在环化和热解过程中形成,当母体循环通过呋喃的损失分解,在逆狄尔斯-阿尔德反应中得到 2-4。以顺式或反式-2-芳酰基环己烷羧酸为起始化合物,形成了1-芳酰基六氢异吲哚-3-酮(5-8);苯基取代的衍生物得到非对映体混合物。新化合物的结构通过核磁共振光谱确定,对于 3 和 6,也通过单晶 X 射线结构测定确定。