光学活性N-肉桂酰R(S)-4-异丙基四氢噻唑-2-硫酮的合成及其量子化学的研究

Study on Synthesis and Quantum Chemistry of R (S) -N - Cinnamyl - 4 - isopropyl Thiazolidine - 2 - thione

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。

Aminoalcohols R - 3 - methyl - 2 - amino - butyl alcohol 2a - 15. 18, S - 3 -methyl - 2 - amino - butyl alcohol 2b + 16.96 were prepared by the reduction of D or L - valine methyl ester. The reduction was carried out with KBH4 and CaCl2. R - 4 - isopropylthiazolidine - 2 -thione 3a,20 + 37.00 and S - 4 - isopropylthiazolidine - 2 - thione 3b, [a]20 - 36.90 were obtained by refluxing a solution of R or S - 3 - methyl - 2 - aminobutylacohol, CSa and KOH. The R - N -cinnamyl-4 - isopropyl thiazolidine - 2 - thione 4a, [a]20 - 169. 72 and S - N - cinnamyl - 4 -isopropylthiazolidine- 2 - thione 4b, [a]20 + 173. 20 was easily prepared by dehydro chlorination between cinnamyl chloride and R or S - 4 - isopropylthiazolidine - 2 - thione under the presence of Et3N. The electronic structure of products and reactants were studied by molecular orbital PM3 method. The reaction enthalpies and optimized configuration for products were obtained.