R(-)四氢噻唑-2-硫酮-4-羧酸对D,L-氨基酸酯拆分的研究

Studies on the Resolution of Racemic Amino Acid Esters by a New Resolving Agent R (-)Thiazolidine 2 thione 4 carboxylic Acid

以新手性拆分试剂Ｒ（－）四氢噻唑－２－硫酮－４－羧酸［简称Ｒ（－）ＴＴＣＡ］对Ｄ，Ｌ－氨基酸酯进行手性拆分，分别得到（Ｒ）ＴＴＣＡ氨基酸酯盐１ａ＿１ｆ（［α］２０Ｄ＝－３０．４０°～－４２．７０°）及光学活性氨基酸酯２ａ＿２ｆ，其光学纯度为３５．４％～７５．８％．由１ａ＿１ｆ在碱存在下分解出２ａ＿２ｆ的对映体３ａ＿３ｆ，光学纯度为３９．５０％～６９．１０％．用半经验的量子化学ＰＭ３方法研究了氨基的碱性、中间产物铵盐生成热和稳定性．

Amino acid esters were resolved by a new resolving agent R (-)thiazolidine 2 thione 4 carboxylic acid R (-)TTCA . The optically active R (-)TTCA amino acid ester salts 1a_1f, α 20 D=-30.40°￣-42.70° and optically active amino acid esters 2a_2f( e.e.: 35 40%￣75 80%) were obtained. When 1a_1f reacted with aqueous NaOH, optically active amino acid esters 3a_3f( e.e : 39.50%￣69.10%) were separated. The basicity of the amino group of amino acid esters and the formation heats of ammonium salts of amino acid ester have been studied using semiempirical quantum chemistry PM3 methods.