Thiazolidine-2,4-dicarboxylic acid and its esters: Synthesis, in solution behaviour and regioselective cyclocondensation
作者:Bernard Refouvelet、Jean-FranÇOis Robert、Jacques Couquelet、Pierre Tronche
DOI:10.1002/jhet.5570310114
日期:1994.1
Thiazolidine-2,4-dicarboxylic acid 2 was obtained as a diastereoisomeric mixture from the condensation of glyoxylic acid with L(-)R-cysteine 1. In solution behaviour studies suggested that the reaction proceeded through an acid catalyzed epimerization mechanism. The methyl esterification of 2 was stereoselective, which can be explained by an interconversion of 2a via a ring seco intermediate. Condensation
由乙醛酸与L(-)R-半胱氨酸1的缩合得到作为非对映异构体混合物的噻唑烷-2,4-二羧酸2。在溶液中的行为研究表明该反应通过酸催化的差向异构机理进行。的甲基酯化2是立体选择性,其可通过的互变来解释图2a通过一个环开环中间体。二甲基酯3或不对称二酯4与异氰酸苯酯的缩合产生相同的乙内酰脲5。二酯3或4的N-酰化 随后与苄胺的反应是区域选择性的,导致双环衍生物8-10。