The Synthesis of enantiomerically pure novel liquid crystal compounds containing the bis(trifluoromethyl)alkanediol moiety.

蚂蚁铁电液晶化合物（afcl）具有手性1,1,1-三氟甲基-2-烷醇部分，是一种重要的高速开关器件。Kusumoto和他的同事最近合成了独特的二聚体aflc分子，该分子含有光学活性的双（三氟甲基）烷二醇作为手性核心单元。然而，所报道的制备光学纯双（三氟甲基）烷二醇的方法需要使用高效液相色谱对手性相进行讨厌的分解过程。我们以前报道过南极假丝酵母脂肪酶催化具有完全对映选择性的外消旋1,1,1-三氟-2-烷醇的反式酯化反应。我们还更有效地实现了醋酸酯的水解。我们接下来尝试用醋酸乙烯酯作为酰基供体在有机溶剂中进行二醇1的反式酯化反应。然而，没有发生反式酯化反应。幸运的是，（±）-1的水解反应进行顺利，使单乙酸酯和二醇具有有效的对映选择性。报道了脂肪酶催化双（三氟甲基）烷二醇水解反应的结果。以该反应获得的旋光性双（三氟甲基）-烷二醇为原料，合成了新型二聚体型afcl。

Ant ferroelectric liquid crystal compounds(AFCLs), which possess a chiral 1,1,1-trifluoromethyl-2-alkanol moiety, are known to be important high-speed switching devices. Kusumoto and his colleagues recently the synthesis of unique dimeric AFLCs molecules which contain optically active bis(trifluoromethyl)alkanediols as chiral core units. The reported means for preparing optically pure bis(trifluoromethyl)alkanediols, however, required a nuisance resolution process using HPLC on chiral phase. We previously reported that Candida antarctica lipase catalyzed trans-esterification of racemic 1,1,1-trifluoro-2-alkanols with perfect enantioselectivity. We also achieved the hydrolysis of acetate more effectively. We next attempted trans-sterification of diol 1 in organic solvent using vinyl acetate as an acyl donor. Trans-esterification, however, did not take place. Fortunately, hydrolysis reaction of (±)-1 proceeded smoothly to provide monoacetate and diol with efficient enantioselectivity. We report the results of lipase-catalyzed hydrolysis reaction of bis(trifluoromethyl)alkanediols. Using optically active bis(trifluormethyl)-alkanediols obtained in this reaction as starting materials, synthesis of novel dimer type AFCLs has been demonstrated.