Innovative Structure Conversion of Optically Active Amino Acids by Electrochemical Oxidation and Its Utilization in Organic Synthesis

光纯有机化合物的合成是当前有机合成研究的热点之一。在本研究中，电化学氧化是将容易获得的α-氨基酸转化为新的光学活性中间体的关键步骤，在有机合成中进一步阐述如下。(1)以电化学氧化为关键步骤，将l -蛋白和l -赖氨酸衍生物转化为旋光性α-烷基脯氨酸和α-烷基油酸衍生物。(2)利用l-赖氨酸衍生物电化学氧化法制备的氧化产物，制备了具有光学活性的无环ω-羧基-α-烷基-α-氨基酸和新的光学活性助剂。(3)以l -缬氨酸为原料，a-甲氧基哌啶衍生物与n-苯基乙酰氧恶唑烷酮形成碳-碳键，制备了具有高对映选择性的旋光性β-氨基酸（d-三-哌醋甲酯）。(4)提出了适合霍夫曼重排的新反应条件。以2,2,2-三氟乙醇（TFEOH）为溶剂，采用电化学方法建立了反应条件。在此反应条件下，l -谷氨酰胺酯衍生物在不损失原有光学纯度的情况下有效地转化为2,4-二氨基丁酸酯。此外，TFEOH中的霍夫曼重排产物三氟乙氧基羰基胺是不对称脲的前体。(5)某些旋光性环α-氨基酸在非kolbe反应中存在手性记忆。(6)开发了一种高效的环氨基化合物Cα-Cβ键试剂，并将其应用于l -枝油酸衍生物的开环反应。

Synthesis of optically pure organic compounds is one of topics in current organic synthesis. In this study, electrochemical oxidation was used as a key step for the transformation of easily available α-amino acids to new optically active intermediates, which were further elaborated in organic synthesis as described below.(1) L-Protein and L-lysine derivatives were converted to optically active α-alkylproline and α-alkylpipecolinic acid derivatives by using electrochemical oxidation as a key step. (2) Optically active acyclic ω-carboxyl-α-alkyl-α-amino acids and new optically active auxiliary were prepared through oxidation products that were prepared by electrochemical oxidation of L-lysine derivative. (3) Optically active β-amino acid (d-threo-methylphenidate) was prepared with a high enantioselectivity by the carbon-carbon bond formation between a-methoxypiperidine derivative and N-phenylacetyloxazolidinone prepared from L-valine. (4) A new reaction condition appropriate to the Hofmann rearrangement was exploited. The reaction condition was created by using an electrochemical method in which 2,2,2-trifluoroethanol (TFEOH) was used as a solvent. Under the reaction condition, L-Glutamine ester derivative was efficiently converted to 2,4-diaminobutyric acid ester without a loss of the original optical purity. Furthermore, tirflouroethoxycarbonylamines, the Hofmann rearrangement products in TFEOH, were found to be precursors for unsymmetrical ureas. (5) Memory of chirality was observed in the non-Kolbe reaction of some kinds of optically active cyclic α-amino acids. (6) An efficient reagent for the Cα-Cβ bond of cyclic amino compounds was exploited and it was applied to the ring opening of L-pipecolinic acid derivative.