Diastereo- and Regioisomeric Bicyclic Thiohydantions from Chiral 1,3-Thiazolidine-2,4-dicarboxylic acids
作者:István Miskolczi、András Zékány、Ferenc Rantal、Anthony Linden、Katalin E. Kövér、Zoltán Györgydeák
DOI:10.1002/hlca.19980810324
日期:——
Bicyclic thiohydantoins were synthesized in a stereoselective manner by reacting (2R)/(2S)-diastereoisomer mixtures of 1,3-thiazolidine-2,4-dicarboxylic acids or their dimethyl diesters with PhNCS. 5,5-Dimethyl-1,3-thiazolidine-2,4-dicarboxylic acid with PhNCS led to a cyclization involving the CO group at the C(2) center of the thiazolidine ring, while the acid's dimethyl diester gave cyclization
通过使(1R,3-噻唑烷-2,4-二羧酸或其二甲基二酯的(2 R)/(2 S)-非对映异构体混合物与PhNCS反应,以立体选择的方式合成双环巯基乙内酰脲。与PhNCS的5,5-二甲基-1,3-噻唑烷-2,4-二羧酸导致环化反应涉及噻唑烷环C(2)中心的CO基团,而酸的二甲基二酯使环化反应涉及CO组在C(4)。相反,涉及未取代的1,3-噻唑烷-2,4-二羧酸或其二甲基二酯的反应会导致巯基乙内酰脲,其中仅在C(4)处的COO基团发生闭环。与开环方向无关,所有反应仅产生具有(R)-C(2)处的配置。构型分配基于1 H-和13 C-NMR研究,并通过X射线晶体学分析得到证实。