Synthesis of Four Stereoisomers of 1,4-Thiazane-3-carboxylic Acid 1-Oxide<i>via</i>the Asymmetric Transformation (combined isomerization-preferential crystallization) of 1,4-Thiazane-3-carboxylic Acid
作者:Tadashi SHIRAIWA、Kohya TADOKORO、Joji ISHIKAWA、Haruyuki TANAKA、Tooru MASAKI、Hidemoto KUROKAWA
DOI:10.1271/bbb.64.341
日期:2000.1
4-thiazane-3-carboxylic acid 1-oxide (TCA SO), (S)-1,4thiazane-3-carboxylic acid [(S)-TCA], which is one of the precursors, was prepared by the asymmetric transformation (combined isomerization-preferential crystallization) of (RS)-TCA. This asymmetric transformation was used (2R, 3R)-tartaric acid [(R)-TA] as a resolving agent and salicylaldehyde as the epimerization catalyst in propanoic acid at 110 degrees
为了合成1,4-噻嗪-3-羧酸1-氧化物(TCA SO)的四种立体异构体,(S)-1,4-噻嗪-3-羧酸[(S)-TCA]是其中之一。前体是通过(RS)-TCA的不对称转化(异构化-优先组合结晶)制备的。该不对称转化反应是在110℃下使用(2R,3R)-酒石酸[[R] -TA]作为拆分剂,使用水杨醛作为差向异构化催化剂在丙酸中制得的(S)-TCA盐与(R )-TA(100%de),收率超过90%。以(RS)-TCA为起始原料,通过在甲醇中用三乙胺处理该盐,以超过80%的产率获得光学纯的(S)-TCA。另外,(R)-TCA的不对称转化以60-70%的产率得到(S)-TCA。(S)-TCA在稀盐酸中被过氧化氢氧化,以选择性地结晶(1S,3S)-TCA.SO。用三乙胺处理后,使滤液中70%的(1R,3S)-TCA SO与(R)-TA形成盐,得到(1R,3S)-TCA SO为单一非对映异构体。(1R,3R)-和(1S,3R)-TCA