3-Aminoacetylthiazolidine-4-carboxylate esters and their l-thia-4-azaspiro[4.5]decane-3-carboxylate derivatives. Synthesis and stereochemical properties
作者:N. Pellegrini、B. Refouvelet、J.-C. Rouland、J.-F. Robert、B. Bachet
DOI:10.1002/jhet.5570340607
日期:1997.11
Dimethyl thiazolidine-2,4-dicarboxylate 2 and ethyl l-thia-4-azaspiro[4.5]decane-3-carboxylates 3-5 were obtained as a diastereoisomeric mixture while their 3-aminoacetyl derivatives were isolated in only one isomeric form. These reactions of N-acylation were stereoselective, which can be explained by an interconversion of the diastereoisomers via a seco intermediate. The 1H nmr analysis of amides
获得非对映异构体混合物的二甲基噻唑烷-2,4-二羧酸酯2和1-噻吩-4-氮杂螺[4.5]癸烷-3-羧酸乙酯3-5,而它们的3-氨基乙酰基衍生物仅以一种异构体形式分离。N-酰化的这些反应是立体选择性的,这可以通过非对映异构体经由山高中间体的相互转化来解释。酰胺6和11的1 H nmr分析显示同时存在顺式和反式酰胺键构象,而螺酰胺8-10和13-15仅观察到一个顺式构象。