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用KBH_4,CaCl_2为还原剂使D及L缬氨酸甲酯还原得到光学活性产物R-3-甲基-2-氨基丁醇(2a)及S-3-甲基-2-氨基丁醇(2b)。2a,2b同CS_2在KOH存在下反应得到(R)-4-异丙基四氢噻唑-2-硫酮(3a)及(S)-4-异丙基四氢噻唑-2-硫酮(3b)。肉桂酰氯分别同3a及3b在Et_3N存在下反应得到N-肉桂酰(R)-4-异丙基四氢噻唑-2-硫酮(4a)及N-肉桂酰(S)-4-异丙基四氢噻唑-2-硫酮(4b)。用半经验的量子化学PM3方法研究了反应物和产物的电子结构,得到了产物的最优构型和电荷键序分布以及反应焓变。
D-and L-valine methyl esters were reduced with KBH 4 and CaCl 2 as reducing agents to obtain optically active products R-3-methyl-2-aminobutanol (2a) and S-3- 2b). 2a, 2b with CS_2 in the presence of KOH gives (R) -4-isopropylthiazolidine-2-thione (3a) and (S) -4-isopropylthiazolidine- 3b). Cinnamoyl chloride is reacted with 3a and 3b, respectively, in the presence of Et_3N to give N-cinnamoyl (R) -4- isopropylthiazolidin-2-thione (4a) and N-cinnamoyl Tetrahydrothiazole-2-thione (4b). The electronic structures of the reactants and products were studied by semi-empirical quantum chemical method (PM3). The optimal configurations of the products and charge-order distribution as well as the enthalpy change were obtained.