Michael-Induced Ring Closure to 2-Azidocyclopropane-1,1-dicarboxylates and their Staudinger Reduction to 5-Alkoxy-3-(alkoxycarbonyl)pyrrolidin-2-ones
作者:Norbert De Kimpe、Sven Mangelinckx
DOI:10.1055/s-2006-926259
日期:——
synthesis of new β-azidocyclopropanedicarboxylates, a rather unexplored class of conformationally constrained N-protected β-aminocyclopropanecarboxylic acid derivatives, is described. Michael-induced ring closure (MIRC) of sodium azide to 2-bromoalkylidenemalonates in alcoholic solvents leads to 3,3-dialkyl-2-azidocyclopropane-1,1-dicarboxylates, whereas other polar solvents give increasing amounts of competitive
描述了一种新的 β-叠氮基环丙烷二羧酸酯的简单而简短的合成,这是一类相当未开发的构象受限的 N-保护的 β-氨基环丙烷羧酸衍生物。在醇类溶剂中,叠氮化钠与 2-溴亚烷基丙二酸的迈克尔诱导闭环 (MIRC) 产生 3,3-二烷基-2-叠氮环丙烷-1,1-二羧酸盐,而其他极性溶剂会产生越来越多的竞争性 2-叠氮亚烷基丙二酸酯。在还原条件下研究了叠氮环丙烷的反应性,从而可以轻松获得 5-烷氧基-3-(烷氧基羰基)吡咯烷-2-酮的非对映异构混合物。